Security+ Ports and Protocols Quiz: 75 Practice Questions and Answers
75 questions for the Security+ SY0-701 exam, each answer explained. Watch it here, try the questions yourself, or read the transcript.
Questions in this video
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Question 1 Play from 00:00
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Why A is wrong
UDP 1701 is L2TP.
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Why B is wrong
UDP 500 is IKE.
Right, C is the answer.
Why C is right
PPTP uses TCP 1723. It is outdated and considered insecure.
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Why D is wrong
TCP 3389 is RDP.
Question 2 Play from 01:13
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Why A is wrong
Port 20 carries data in active mode FTP.
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Why B is wrong
Port 22 is SSH and SFTP.
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Why C is wrong
Port 69 is TFTP.
Right, D is the answer.
Why D is right
FTP sends its commands, including the login, over TCP 21.
Question 3 Play from 02:14
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Why A is wrong
RADIUS encrypts only the password and is mainly used for network access.
Right, B is the answer.
Why B is right
TACACS+ encrypts the entire payload and separates authentication, authorization and accounting, so it can authorize each command.
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Why C is wrong
LDAP is a directory lookup protocol.
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Why D is wrong
Kerberos issues tickets for logins, not per-command device authorization.
Question 4 Play from 03:45
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Why A is wrong
Port 161 is SNMP.
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Why B is wrong
Port 69 is TFTP.
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Why C is wrong
Port 514 is syslog.
Right, D is the answer.
Why D is right
NTP keeps clocks in sync over UDP port 123.
Question 5 Play from 04:41
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Why A is wrong
Port 88 is Kerberos.
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Why B is wrong
Port 636 is LDAP over TLS.
Right, C is the answer.
Why C is right
LDAP queries a directory such as Active Directory over port 389.
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Why D is wrong
Port 445 is SMB.
Question 6 Play from 05:43
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Why A is wrong
UDP 500 is IKE.
Right, B is the answer.
Why B is right
L2TP uses UDP 1701 and is normally paired with IPsec for encryption.
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Why C is wrong
TCP 443 is HTTPS.
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Why D is wrong
TCP 1723 is PPTP.
Question 7 Play from 06:54
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Why A is wrong
IMAP on 143 is not encrypted either.
Right, B is the answer.
Why B is right
LDAPS on 636 is the TLS-protected version of LDAP on 389.
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Why C is wrong
FTP is also cleartext and is not a shell.
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Why D is wrong
Syslog is a logging protocol, not secure SNMP.
Question 8 Play from 08:24
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Why A is right
802.1X uses a RADIUS server as the authentication server, and RADIUS authentication listens on UDP 1812.
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Why B is wrong
TACACS+ uses TCP 49 and is mainly for device administration.
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Why C is wrong
LDAP uses port 389.
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Why D is wrong
Kerberos uses port 88.
Question 9 Play from 09:35
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Why A is wrong
GRE is a tunneling protocol.
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Why B is wrong
ICMP carries control messages such as ping.
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Why C is wrong
TCP is not used for standard NTP.
Right, D is the answer.
Why D is right
NTP runs over UDP port 123.
Question 10 Play from 10:34
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Why A is wrong
Port 514 is syslog.
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Why B is wrong
Port 162 receives SNMP traps at the manager.
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Why C is wrong
Port 123 is NTP.
Right, D is the answer.
Why D is right
SNMP agents listen for get and set requests on UDP 161.
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Question 11 Play from 11:38
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Why A is wrong
Kerberos uses 88.
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Why B is wrong
MySQL uses 3306.
Right, C is the answer.
Why C is right
TCP 1433 is the default Microsoft SQL Server port.
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Why D is wrong
LDAP uses 389.
Question 12 Play from 12:47
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Why A is wrong
Port 995 is POP3 over TLS.
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Why B is wrong
Port 465 is SMTP over implicit TLS.
Right, C is the answer.
Why C is right
IMAPS, the encrypted form of IMAP, uses TCP port 993.
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Why D is wrong
Port 143 is IMAP without TLS.
Question 13 Play from 13:57
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Why A is wrong
Port 53 is DNS.
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Why B is wrong
Port 69 is TFTP.
Right, C is the answer.
Why C is right
The DHCP server side uses UDP port 67.
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Why D is wrong
Port 68 is the DHCP client side.
Question 14 Play from 14:59
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Why A is wrong
FTPS uses ports 21 or 990.
Right, B is the answer.
Why B is right
SCP copies files over an SSH connection, so it uses TCP 22.
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Why C is wrong
TFTP uses UDP 69.
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Why D is wrong
FTP uses ports 20 and 21.
Question 15 Play from 16:05
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Why A is wrong
POP3S is encrypted, but POP3 does not keep folders in sync.
Right, B is the answer.
Why B is right
IMAP keeps mail and folders on the server so every device sees the same view, and IMAPS on 993 adds TLS.
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Why C is wrong
SMTP sends mail, it does not read it.
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Why D is wrong
POP3 downloads mail to one device and is not encrypted.
Question 16 Play from 17:33
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Why A is wrong
TFTP uses UDP 69, not TCP 443.
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Why B is wrong
TFTP traffic can be routed like any other UDP traffic.
Right, C is the answer.
Why C is right
TFTP has no login and no encryption, so anyone on the path can read or alter the files.
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Why D is wrong
TFTP has no certificate support at all.
Question 17 Play from 18:53
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Why A is wrong
Port 1433 is Microsoft SQL Server.
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Why B is wrong
Port 3389 is RDP.
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Why C is wrong
Port 5432 is PostgreSQL.
Right, D is the answer.
Why D is right
MySQL listens on TCP 3306 by default.
Question 18 Play from 19:53
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Why A is wrong
GRE is a tunneling protocol.
Right, B is the answer.
Why B is right
TACACS+ runs over TCP port 49, which gives it reliable delivery.
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Why C is wrong
UDP is what RADIUS uses.
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Why D is wrong
ICMP carries control messages such as ping.
Question 19 Play from 20:56
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Why A is wrong
Port 3389 is RDP.
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Why B is wrong
Port 3306 is MySQL.
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Why C is wrong
Port 5432 is PostgreSQL.
Right, D is the answer.
Why D is right
Microsoft SQL Server listens on TCP 1433 by default.
Question 20 Play from 21:57
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Why A is right
Port 993 is IMAPS, the encrypted version of IMAP.
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Why B is wrong
SMTP over implicit TLS uses 465.
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Why C is wrong
LDAP over TLS uses 636.
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Why D is wrong
POP3 over TLS uses 995.
Question 21 Play from 23:11
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Why A is wrong
UDP 162 is for SNMP traps.
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Why B is wrong
TCP 6514 is syslog over TLS.
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Why C is wrong
TCP 443 is HTTPS.
Right, D is the answer.
Why D is right
Classic syslog sends log messages over UDP 514, with no encryption.
Question 22 Play from 24:22
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Why A is wrong
Port 5900 is VNC.
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Why B is wrong
Port 1723 is PPTP.
Right, C is the answer.
Why C is right
SIP sets up VoIP calls on port 5060.
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Why D is wrong
Port 5061 is SIP over TLS.
Question 23 Play from 25:26
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Why A is wrong
Port 123 is NTP.
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Why B is wrong
Port 53 is DNS.
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Why C is wrong
Port 443 is HTTPS, often needed for public sites.
Right, D is the answer.
Why D is right
Worms such as WannaCry spread through SMB on TCP 445, which should never be open to the internet.
Question 24 Play from 26:37
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Why A is right
RADIUS sends accounting data, such as session start and stop records, on UDP port 1813.
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Why B is wrong
Port 1812 is RADIUS authentication.
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Why C is wrong
Port 49 is TACACS+.
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Why D is wrong
Port 88 is Kerberos.
Question 25 Play from 27:40
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Why A is wrong
Microsoft SQL Server uses 1433.
Right, B is the answer.
Why B is right
TCP 3306 is MySQL, and a database should not be reachable from the internet.
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Why C is wrong
SMB uses 445.
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Why D is wrong
Remote Desktop uses 3389.
Question 26 Play from 28:47
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Why A is wrong
Port 853 is DNS over TLS.
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Why B is wrong
Port 8443 is only an alternate HTTPS port.
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Why C is wrong
Port 53 is plain DNS.
Right, D is the answer.
Why D is right
DNS over HTTPS sends queries as HTTPS requests, so it uses port 443 and blends in with web traffic.
Question 27 Play from 30:07
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Why A is right
Zone transfers copy whole zones between DNS servers and run over TCP 53.
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Why B is wrong
Clock sync is done by NTP.
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Why C is wrong
Ordinary lookups normally use UDP.
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Why D is wrong
Address leases come from DHCP.
Question 28 Play from 31:23
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Why A is wrong
VoIP gateways use SIP on 5060.
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Why B is wrong
Web proxies often use 8080.
Right, C is the answer.
Why C is right
Port 88 is Kerberos, so the host is likely a domain controller acting as the KDC.
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Why D is wrong
Databases use ports such as 1433 or 3306.
Question 29 Play from 32:39
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Why A is wrong
DNS uses port 53.
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Why B is wrong
SMTP uses port 25.
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Why C is wrong
SSH uses port 22.
Right, D is the answer.
Why D is right
Telnet uses port 23 and sends usernames and passwords in cleartext, which is why SSH replaced it.
Question 30 Play from 33:39
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Why A is wrong
Port 25 must stay open for a mail server to receive mail.
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Why B is wrong
HTTPS on 443 must stay open for a public website.
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Why C is wrong
Port 53 must stay open for a public DNS server.
Right, D is the answer.
Why D is right
Exposed RDP on 3389 is a frequent target for password guessing and ransomware gangs; put it behind a VPN instead.
Question 31 Play from 34:59
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Why A is right
Allowing only TCP 443 limits the server to HTTPS, following least privilege.
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Why B is wrong
An any-to-any DNS rule is far too broad.
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Why C is wrong
Port 80 is unencrypted and Telnet on 23 should never be exposed.
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Why D is wrong
Exposing RDP to the internet invites brute-force attacks.
Question 32 Play from 36:29
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Why A is right
RADIUS runs over UDP, on ports 1812 and 1813.
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Why B is wrong
ICMP carries control messages such as ping.
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Why C is wrong
TCP is what TACACS+ uses.
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Why D is wrong
GRE is a tunneling protocol.
Question 33 Play from 37:31
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Why A is wrong
TCP 1723 is PPTP.
Right, B is the answer.
Why B is right
NAT traversal wraps IPsec traffic in UDP 4500 so it survives address translation.
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Why C is wrong
UDP 500 is the initial IKE exchange.
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Why D is wrong
UDP 1701 is L2TP.
Question 34 Play from 38:46
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Why A is right
DNS uses port 53, mostly over UDP for lookups.
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Why B is wrong
Port 161 is SNMP.
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Why C is wrong
Port 67 is the DHCP server.
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Why D is wrong
Port 123 is NTP.
Question 35 Play from 39:46
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Why A is wrong
Port 21 is plain FTP, or explicit FTPS that upgrades later.
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Why B is wrong
Port 22 is SSH and SFTP.
Right, C is the answer.
Why C is right
Implicit FTPS starts TLS immediately, with the control channel on port 990.
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Why D is wrong
Port 989 is the implicit FTPS data channel.
Question 36 Play from 40:54
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Why A is wrong
Port 22 is SSH, a command-line session.
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Why B is wrong
Port 445 is SMB file sharing.
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Why C is wrong
Port 5900 is VNC, a different remote desktop tool.
Right, D is the answer.
Why D is right
Microsoft Remote Desktop Protocol listens on port 3389.
Question 37 Play from 42:09
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Why A is wrong
Port 389 is LDAP, a directory service.
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Why B is wrong
Port 110 is POP3, used to download mail.
Right, C is the answer.
Why C is right
Server-to-server mail transfer with SMTP uses TCP port 25.
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Why D is wrong
Port 143 is IMAP, used to read mail.
Question 38 Play from 43:13
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Why A is wrong
Port 990 is FTPS.
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Why B is wrong
Port 993 is IMAP over TLS.
Right, C is the answer.
Why C is right
POP3S, the encrypted form of POP3, uses TCP port 995.
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Why D is wrong
Port 110 is plain POP3.
Question 39 Play from 44:19
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Why A is wrong
Port 139 is the legacy NetBIOS session service.
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Why B is wrong
Port 3389 is RDP.
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Why C is wrong
Port 2049 is NFS.
Right, D is the answer.
Why D is right
Modern SMB runs directly over TCP 445.
Question 40 Play from 45:21
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Why A is right
UDP 161 is where SNMP agents receive management queries.
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Why B is wrong
NTP uses 123.
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Why C is wrong
Syslog uses 514.
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Why D is wrong
DNS uses 53.
Question 41 Play from 46:27
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Why A is wrong
Ports 1812 and 1813 are RADIUS.
Right, B is the answer.
Why B is right
NetBIOS name, datagram and session services use ports 137, 138 and 139.
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Why C is wrong
Ports 161 and 162 are SNMP.
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Why D is wrong
Port 445 is SMB directly over TCP.
Question 42 Play from 47:43
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Why A is wrong
Port 21 is the FTP control channel, used for file transfer.
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Why B is wrong
Port 3389 is RDP, a graphical Windows desktop, not a Linux shell.
Right, C is the answer.
Why C is right
SSH runs on TCP port 22 and encrypts the whole session, including the login.
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Why D is wrong
Port 23 is Telnet, which sends everything in cleartext.
Question 43 Play from 48:55
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Why A is right
SNMP traps are sent to the manager on UDP 162.
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Why B is wrong
Port 6514 is syslog over TLS.
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Why C is wrong
Port 161 is where agents receive queries.
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Why D is wrong
Port 514 is syslog.
Question 44 Play from 50:02
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Why A is wrong
Port 993 is IMAPS, which retrieves mail.
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Why B is wrong
Port 25 is mainly for relay between mail servers.
Right, C is the answer.
Why C is right
Port 587 is the message submission port: the client authenticates and uses STARTTLS to encrypt the session.
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Why D is wrong
Port 110 is POP3, which retrieves mail.
Question 45 Play from 51:21
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Why A is right
TLS VPNs use TCP 443, the same port as HTTPS, which is rarely blocked.
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Why B is wrong
TCP 1723 is PPTP.
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Why C is wrong
UDP 500 is IKE for IPsec.
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Why D is wrong
UDP 1701 is L2TP.
Question 46 Play from 52:39
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Why A is wrong
Syslog uses port 514.
Right, B is the answer.
Why B is right
Port 8080 is a common alternate port for HTTP, often used by proxies and test web servers.
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Why C is wrong
Secure Shell uses port 22.
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Why D is wrong
Kerberos uses port 88.
Question 47 Play from 53:51
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Why A is right
UDP 514 is the default syslog port.
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Why B is wrong
NTP uses port 123.
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Why C is wrong
SNMP traps use port 162.
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Why D is wrong
TFTP uses port 69.
Question 48 Play from 54:55
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Why A is wrong
Port 389 is plain LDAP.
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Why B is wrong
Port 993 is IMAP over TLS.
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Why C is wrong
Port 443 is HTTPS.
Right, D is the answer.
Why D is right
LDAPS, which is LDAP over TLS, uses port 636.
Question 49 Play from 56:03
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Why A is right
SFTP is a file transfer protocol carried by SSH, so it uses port 22 and is encrypted.
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Why B is wrong
TFTP uses UDP 69 with no security.
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Why C is wrong
FTPS is FTP with TLS, on ports 21 or 990.
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Why D is wrong
FTP uses ports 20 and 21 with no encryption.
Question 50 Play from 57:18
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Why A is right
IMAP moves from 143 to 993 when it runs over TLS.
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Why B is wrong
993 is IMAPS; POP3S is 995.
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Why C is wrong
LDAPS uses 636, not 443.
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Why D is wrong
995 is POP3S, not IMAPS.
Question 51 Play from 58:53
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Why A is wrong
Port 22 is SSH and SFTP.
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Why B is wrong
Port 990 is FTPS.
Right, C is the answer.
Why C is right
In active mode, the server sends data from port 20.
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Why D is wrong
Port 21 is the control channel.
Question 52 Play from 59:52
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Why A is wrong
DNS uses port 53.
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Why B is wrong
HTTPS uses port 443.
Right, C is the answer.
Why C is right
Port 80 is the default for plain HTTP, so the content crosses the network unencrypted.
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Why D is wrong
SSH uses port 22.
Question 53 Play from 1:01:09
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Why A is wrong
HTTP is unencrypted web traffic.
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Why B is wrong
TFTP transfers files without security.
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Why C is wrong
SNMPv1 is cleartext monitoring, not a shell.
Right, D is the answer.
Why D is right
SSH gives the same command-line access as Telnet but encrypts the whole session.
Question 54 Play from 1:02:14
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Why A is wrong
TCP 22 is SSH.
Right, B is the answer.
Why B is right
TFTP is a very simple file transfer protocol on UDP 69.
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Why C is wrong
UDP 67 is the DHCP server.
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Why D is wrong
TCP 21 is FTP.
Question 55 Play from 1:03:19
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Why A is right
Restricting port 53 to the approved DNS server stops clients from using outside resolvers that bypass company filtering.
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Why B is wrong
UDP 123 is NTP, not DNS.
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Why C is wrong
TCP 389 is LDAP, not DNS.
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Why D is wrong
Allowing 53 to anywhere lets clients bypass the company's DNS server.
Question 56 Play from 1:04:46
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Why A is wrong
UDP 1701 is L2TP.
Right, B is the answer.
Why B is right
IKE negotiates IPsec keys and security associations on UDP 500.
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Why C is wrong
TCP 443 is HTTPS, used by TLS VPNs.
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Why D is wrong
UDP 4500 is used when NAT traversal is needed.
Question 57 Play from 1:05:59
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Why A is wrong
UDP 500 handles only the IKE key exchange, not the encrypted data.
Right, B is the answer.
Why B is right
ESP is its own IP protocol, number 50, not a TCP or UDP port.
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Why C is wrong
TCP 443 is HTTPS.
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Why D is wrong
ESP does not run over TCP.
Question 58 Play from 1:07:15
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Why A is right
RADIUS authentication runs on UDP port 1812.
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Why B is wrong
Port 1813 is RADIUS accounting.
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Why C is wrong
Port 49 is TACACS+.
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Why D is wrong
Port 389 is LDAP.
Question 59 Play from 1:08:16
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Why A is right
HTTPS is HTTP protected by TLS, and its default port is TCP 443.
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Why B is wrong
Port 8080 is a common alternate port for HTTP or proxies.
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Why C is wrong
Port 853 is DNS over TLS.
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Why D is wrong
Port 80 is plain, unencrypted HTTP.
Question 60 Play from 1:09:26
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Why A is wrong
Port 5060 is SIP.
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Why B is wrong
Port 3389 is Microsoft RDP.
Right, C is the answer.
Why C is right
VNC remote desktop listens on TCP 5900.
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Why D is wrong
Port 22 is SSH.
Question 61 Play from 1:10:32
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Why A is wrong
Port 21 is cleartext FTP.
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Why B is wrong
Port 80 is cleartext HTTP.
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Why C is wrong
Port 23 is cleartext Telnet.
Right, D is the answer.
Why D is right
SSH on 22, HTTPS on 443 and IMAPS on 993 are all encrypted.
Question 62 Play from 1:11:50
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Why A is wrong
Port 465 is SMTP over implicit TLS.
Right, B is the answer.
Why B is right
Port 143 is IMAP, which reads mail from the server.
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Why C is wrong
Port 587 is SMTP submission.
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Why D is wrong
Port 25 is SMTP relay.
Question 63 Play from 1:12:52
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Why A is wrong
LDAP uses 389.
Right, B is the answer.
Why B is right
TCP 445 is the SMB file and printer sharing service.
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Why C is wrong
RDP uses 3389.
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Why D is wrong
HTTPS uses 443.
Question 64 Play from 1:13:55
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Why A is wrong
Port 636 is LDAP over TLS.
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Why B is wrong
Port 53 is ordinary unencrypted DNS.
Right, C is the answer.
Why C is right
DNS over TLS has its own port, TCP 853.
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Why D is wrong
Port 443 is used by DNS over HTTPS, a different method.
Question 65 Play from 1:15:00
Tap an answer. The reason for that answer shows here.
Right, A is the answer.
Why A is right
SNMPv3 adds user authentication and encryption, which earlier versions lack.
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Why B is wrong
The public community string is a well-known default and is not secure.
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Why C is wrong
SNMPv1 uses cleartext community strings.
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Why D is wrong
SNMPv2c also uses cleartext community strings.
Question 66 Play from 1:16:12
Tap an answer. The reason for that answer shows here.
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Why A is wrong
Port 636 is LDAP over TLS.
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Why B is wrong
Port 514 is plain syslog.
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Why C is wrong
Port 162 is for SNMP traps.
Right, D is the answer.
Why D is right
Syslog over TLS uses TCP 6514.
Question 67 Play from 1:17:24
Tap an answer. The reason for that answer shows here.
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Why A is wrong
Port 636 is LDAP over TLS.
Right, B is the answer.
Why B is right
Port 465 carries SMTP with implicit TLS, so the session is encrypted from the first packet.
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Why C is wrong
Port 995 is POP3 over TLS.
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Why D is wrong
Port 587 starts in plaintext and upgrades with STARTTLS.
Question 68 Play from 1:18:38
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Why A is wrong
DHCP hands out IP addresses.
Right, B is the answer.
Why B is right
Kerberos rejects tickets when clocks differ too much, and NTP on UDP 123 keeps them aligned.
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Why C is wrong
Syslog collects log messages.
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Why D is wrong
SNMP monitors and manages devices.
Question 69 Play from 1:19:58
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Why A is wrong
Port 389 is LDAP.
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Why B is wrong
Port 1812 is RADIUS authentication.
Right, C is the answer.
Why C is right
Kerberos clients reach the key distribution center on port 88.
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Why D is wrong
Port 49 is TACACS+.
Question 70 Play from 1:20:57
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Why A is wrong
SSH, FTPS and syslog over TLS are all encrypted.
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Why B is wrong
HTTPS, IMAPS and POP3S are all encrypted.
Right, C is the answer.
Why C is right
FTP on 21, Telnet on 23 and HTTP on 80 all send credentials unencrypted.
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Why D is wrong
SSH, HTTPS and LDAPS are all encrypted.
Question 71 Play from 1:22:25
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Why A is wrong
Port 25 is SMTP.
Right, B is the answer.
Why B is right
Plain IMAP uses TCP 143.
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Why C is wrong
Port 110 is POP3.
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Why D is wrong
Port 993 is IMAP over TLS.
Question 72 Play from 1:23:28
Tap an answer. The reason for that answer shows here.
Right, A is the answer.
Why A is right
Encrypted SIP signaling uses TCP 5061.
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Why B is wrong
Port 5060 is unencrypted SIP.
Not this one. Try another answer.
Why C is wrong
Port 993 is IMAP over TLS.
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Why D is wrong
Port 443 is HTTPS.
Question 73 Play from 1:24:35
Tap an answer. The reason for that answer shows here.
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Why A is wrong
Port 143 is plain IMAP.
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Why B is wrong
Port 25 is SMTP, used for sending.
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Why C is wrong
Port 995 is POP3 over TLS, which is encrypted.
Right, D is the answer.
Why D is right
Plain POP3 uses TCP port 110.
Question 74 Play from 1:25:42
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Why A is wrong
SFTP uses TCP 22.
Right, B is the answer.
Why B is right
PXE network boot commonly pulls the boot file with TFTP on UDP 69.
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Why C is wrong
FTP uses TCP 20 and 21.
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Why D is wrong
HTTP uses TCP 80.
Question 75 Play from 1:26:58
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Right, A is the answer.
Why A is right
DHCP servers listen on UDP 67 and clients use UDP 68.
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Why B is wrong
UDP 53 is DNS.
Not this one. Try another answer.
Why C is wrong
UDP 123 is NTP.
Not this one. Try another answer.
Why D is wrong
UDP 161 and 162 are SNMP.
Transcript
Play from 00:00 Question 1. Which port does the legacy PPTP VPN use for its control connection? Here are the options. Option A. UDP 1701. Option B. UDP 500. Option C. TCP 1723. Option D. TCP 3389. Pause the video now if you want time to think about the answer.
The correct answer is C. TCP 1723. PPTP uses TCP 1723. It is outdated and considered insecure. Now, why are the other options incorrect? Option A is incorrect. UDP 1701 is L2TP. Option B is incorrect. UDP 500 is IKE. Option D is incorrect. TCP 3389 is RDP. Therefore, C, TCP 1723, is the correct answer.
Play from 01:13 Question 2. Which port does the FTP control channel use? Here are the options. Option A. 20. Option B. 22. Option C. 69. Option D. 21. Pause the video now if you want time to think about the answer.
The correct answer is D. 21. FTP sends its commands, including the login, over TCP 21. Now, why are the other options incorrect? Option A is incorrect. Port 20 carries data in active mode FTP. Option B is incorrect. Port 22 is SSH and SFTP. Option C is incorrect. Port 69 is TFTP. Therefore, D, 21, is the correct answer.
Play from 02:14 Question 3. A network team wants admins who log in to switches to be authorized command by command, with the whole session payload encrypted. Which protocol and port fit? Here are the options. Option A. RADIUS on UDP 1812. Option B. TACACS+ on TCP 49. Option C. LDAP on port 389. Option D. Kerberos on port 88. Pause the video now if you want time to think about the answer.
The correct answer is B. TACACS+ on TCP 49. TACACS+ encrypts the entire payload and separates authentication, authorization and accounting, so it can authorize each command. Now, why are the other options incorrect? Option A is incorrect. RADIUS encrypts only the password and is mainly used for network access. Option C is incorrect. LDAP is a directory lookup protocol. Option D is incorrect. Kerberos issues tickets for logins, not per-command device authorization. Therefore, B, TACACS+ on TCP 49, is the correct answer.
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Play from 03:45 Question 4. Which port does NTP use? Here are the options. Option A. 161. Option B. 69. Option C. 514. Option D. 123. Pause the video now if you want time to think about the answer.
The correct answer is D. 123. NTP keeps clocks in sync over UDP port 123. Now, why are the other options incorrect? Option A is incorrect. Port 161 is SNMP. Option B is incorrect. Port 69 is TFTP. Option C is incorrect. Port 514 is syslog. Therefore, D, 123, is the correct answer.
Play from 04:41 Question 5. Which port does LDAP use by default? Here are the options. Option A. 88. Option B. 636. Option C. 389. Option D. 445. Pause the video now if you want time to think about the answer.
The correct answer is C. 389. LDAP queries a directory such as Active Directory over port 389. Now, why are the other options incorrect? Option A is incorrect. Port 88 is Kerberos. Option B is incorrect. Port 636 is LDAP over TLS. Option D is incorrect. Port 445 is SMB. Therefore, C, 389, is the correct answer.
Play from 05:43 Question 6. Which port does L2TP use? Here are the options. Option A. UDP 500. Option B. UDP 1701. Option C. TCP 443. Option D. TCP 1723. Pause the video now if you want time to think about the answer.
The correct answer is B. UDP 1701. L2TP uses UDP 1701 and is normally paired with IPsec for encryption. Now, why are the other options incorrect? Option A is incorrect. UDP 500 is IKE. Option C is incorrect. TCP 443 is HTTPS. Option D is incorrect. TCP 1723 is PPTP. Therefore, B, UDP 1701, is the correct answer.
Play from 06:54 Question 7. Which pair shows an insecure protocol followed by its secure replacement, with the correct ports? Here are the options. Option A. POP3 110, then IMAP 143. Option B. LDAP 389, then LDAPS 636. Option C. Telnet 23, then FTP 21. Option D. SNMP 161, then syslog 514. Pause the video now if you want time to think about the answer.
The correct answer is B. LDAP 389, then LDAPS 636. LDAPS on 636 is the TLS-protected version of LDAP on 389. Now, why are the other options incorrect? Option A is incorrect. IMAP on 143 is not encrypted either. Option C is incorrect. FTP is also cleartext and is not a shell. Option D is incorrect. Syslog is a logging protocol, not secure SNMP. Therefore, B, LDAP 389, then LDAPS 636, is the correct answer.
Play from 08:24 Question 8. A wireless controller sends 802.1X login requests to a central server on UDP port 1812. What kind of server is it? Here are the options. Option A. RADIUS. Option B. TACACS+. Option C. LDAP. Option D. Kerberos. Pause the video now if you want time to think about the answer.
The correct answer is A. RADIUS. 802.1X uses a RADIUS server as the authentication server, and RADIUS authentication listens on UDP 1812. Now, why are the other options incorrect? Option B is incorrect. TACACS+ uses TCP 49 and is mainly for device administration. Option C is incorrect. LDAP uses port 389. Option D is incorrect. Kerberos uses port 88. Therefore, A, RADIUS, is the correct answer.
Play from 09:35 Question 9. Which transport protocol does NTP use? Here are the options. Option A. GRE. Option B. ICMP. Option C. TCP. Option D. UDP. Pause the video now if you want time to think about the answer.
The correct answer is D. UDP. NTP runs over UDP port 123. Now, why are the other options incorrect? Option A is incorrect. GRE is a tunneling protocol. Option B is incorrect. ICMP carries control messages such as ping. Option C is incorrect. TCP is not used for standard NTP. Therefore, D, UDP, is the correct answer.
Play from 10:34 Question 10. On which port does an SNMP agent on a router receive queries from a management station? Here are the options. Option A. 514. Option B. 162. Option C. 123. Option D. 161. Pause the video now if you want time to think about the answer.
The correct answer is D. 161. SNMP agents listen for get and set requests on UDP 161. Now, why are the other options incorrect? Option A is incorrect. Port 514 is syslog. Option B is incorrect. Port 162 receives SNMP traps at the manager. Option C is incorrect. Port 123 is NTP. Therefore, D, 161, is the correct answer.
Play from 11:38 Question 11. A scan finds TCP 1433 open on a server. Which service is it most likely running? Here are the options. Option A. Kerberos. Option B. MySQL. Option C. Microsoft SQL Server. Option D. LDAP. Pause the video now if you want time to think about the answer.
The correct answer is C. Microsoft SQL Server. TCP 1433 is the default Microsoft SQL Server port. Now, why are the other options incorrect? Option A is incorrect. Kerberos uses 88. Option B is incorrect. MySQL uses 3306. Option D is incorrect. LDAP uses 389. Therefore, C, Microsoft SQL Server, is the correct answer.
Play from 12:47 Question 12. Which port does IMAP over TLS, also called IMAPS, use? Here are the options. Option A. 995. Option B. 465. Option C. 993. Option D. 143. Pause the video now if you want time to think about the answer.
The correct answer is C. 993. IMAPS, the encrypted form of IMAP, uses TCP port 993. Now, why are the other options incorrect? Option A is incorrect. Port 995 is POP3 over TLS. Option B is incorrect. Port 465 is SMTP over implicit TLS. Option D is incorrect. Port 143 is IMAP without TLS. Therefore, C, 993, is the correct answer.
Play from 13:57 Question 13. On which port does a DHCP server listen for client requests? Here are the options. Option A. 53. Option B. 69. Option C. 67. Option D. 68. Pause the video now if you want time to think about the answer.
The correct answer is C. 67. The DHCP server side uses UDP port 67. Now, why are the other options incorrect? Option A is incorrect. Port 53 is DNS. Option B is incorrect. Port 69 is TFTP. Option D is incorrect. Port 68 is the DHCP client side. Therefore, C, 67, is the correct answer.
Play from 14:59 Question 14. Which file transfer method uses the same port as SSH? Here are the options. Option A. FTPS. Option B. SCP. Option C. TFTP. Option D. FTP. Pause the video now if you want time to think about the answer.
The correct answer is B. SCP. SCP copies files over an SSH connection, so it uses TCP 22. Now, why are the other options incorrect? Option A is incorrect. FTPS uses ports 21 or 990. Option C is incorrect. TFTP uses UDP 69. Option D is incorrect. FTP uses ports 20 and 21. Therefore, B, SCP, is the correct answer.
Play from 16:05 Question 15. Staff read the same mailbox on a laptop and a phone, and folders must stay in sync on the server. Which choice fits best and is encrypted? Here are the options. Option A. POP3S on port 995. Option B. IMAPS on port 993. Option C. SMTP on port 25. Option D. POP3 on port 110. Pause the video now if you want time to think about the answer.
The correct answer is B. IMAPS on port 993. IMAP keeps mail and folders on the server so every device sees the same view, and IMAPS on 993 adds TLS. Now, why are the other options incorrect? Option A is incorrect. POP3S is encrypted, but POP3 does not keep folders in sync. Option C is incorrect. SMTP sends mail, it does not read it. Option D is incorrect. POP3 downloads mail to one device and is not encrypted. Therefore, B, IMAPS on port 993, is the correct answer.
Play from 17:33 Question 16. A network engineer backs up switch configurations with TFTP. What is the main security concern? Here are the options. Option A. It only works over TCP 443. Option B. It cannot cross a router. Option C. It has no authentication or encryption. Option D. It needs a certificate on every switch. Pause the video now if you want time to think about the answer.
The correct answer is C. It has no authentication or encryption. TFTP has no login and no encryption, so anyone on the path can read or alter the files. Now, why are the other options incorrect? Option A is incorrect. TFTP uses UDP 69, not TCP 443. Option B is incorrect. TFTP traffic can be routed like any other UDP traffic. Option D is incorrect. TFTP has no certificate support at all. Therefore, C, It has no authentication or encryption, is the correct answer.
Play from 18:53 Question 17. What is the default port for MySQL? Here are the options. Option A. 1433. Option B. 3389. Option C. 5432. Option D. 3306. Pause the video now if you want time to think about the answer.
The correct answer is D. 3306. MySQL listens on TCP 3306 by default. Now, why are the other options incorrect? Option A is incorrect. Port 1433 is Microsoft SQL Server. Option B is incorrect. Port 3389 is RDP. Option C is incorrect. Port 5432 is PostgreSQL. Therefore, D, 3306, is the correct answer.
Play from 19:53 Question 18. Which transport protocol does TACACS+ use? Here are the options. Option A. GRE. Option B. TCP. Option C. UDP. Option D. ICMP. Pause the video now if you want time to think about the answer.
The correct answer is B. TCP. TACACS+ runs over TCP port 49, which gives it reliable delivery. Now, why are the other options incorrect? Option A is incorrect. GRE is a tunneling protocol. Option C is incorrect. UDP is what RADIUS uses. Option D is incorrect. ICMP carries control messages such as ping. Therefore, B, TCP, is the correct answer.
Play from 20:56 Question 19. What is the default port for Microsoft SQL Server? Here are the options. Option A. 3389. Option B. 3306. Option C. 5432. Option D. 1433. Pause the video now if you want time to think about the answer.
The correct answer is D. 1433. Microsoft SQL Server listens on TCP 1433 by default. Now, why are the other options incorrect? Option A is incorrect. Port 3389 is RDP. Option B is incorrect. Port 3306 is MySQL. Option C is incorrect. Port 5432 is PostgreSQL. Therefore, D, 1433, is the correct answer.
Play from 21:57 Question 20. Which protocol uses TCP port 993? Here are the options. Option A. IMAP over TLS. Option B. SMTP over TLS. Option C. LDAP over TLS. Option D. POP3 over TLS. Pause the video now if you want time to think about the answer.
The correct answer is A. IMAP over TLS. Port 993 is IMAPS, the encrypted version of IMAP. Now, why are the other options incorrect? Option B is incorrect. SMTP over implicit TLS uses 465. Option C is incorrect. LDAP over TLS uses 636. Option D is incorrect. POP3 over TLS uses 995. Therefore, A, IMAP over TLS, is the correct answer.
Play from 23:11 Question 21. Which port does traditional syslog use? Here are the options. Option A. UDP 162. Option B. TCP 6514. Option C. TCP 443. Option D. UDP 514. Pause the video now if you want time to think about the answer.
The correct answer is D. UDP 514. Classic syslog sends log messages over UDP 514, with no encryption. Now, why are the other options incorrect? Option A is incorrect. UDP 162 is for SNMP traps. Option B is incorrect. TCP 6514 is syslog over TLS. Option C is incorrect. TCP 443 is HTTPS. Therefore, D, UDP 514, is the correct answer.
Play from 24:22 Question 22. Which port does unencrypted SIP use for VoIP call setup? Here are the options. Option A. 5900. Option B. 1723. Option C. 5060. Option D. 5061. Pause the video now if you want time to think about the answer.
The correct answer is C. 5060. SIP sets up VoIP calls on port 5060. Now, why are the other options incorrect? Option A is incorrect. Port 5900 is VNC. Option B is incorrect. Port 1723 is PPTP. Option D is incorrect. Port 5061 is SIP over TLS. Therefore, C, 5060, is the correct answer.
Play from 25:26 Question 23. To stop worms and ransomware spreading through Windows file shares from the internet, which inbound port should the edge firewall block? Here are the options. Option A. 123. Option B. 53. Option C. 443. Option D. 445. Pause the video now if you want time to think about the answer.
The correct answer is D. 445. Worms such as WannaCry spread through SMB on TCP 445, which should never be open to the internet. Now, why are the other options incorrect? Option A is incorrect. Port 123 is NTP. Option B is incorrect. Port 53 is DNS. Option C is incorrect. Port 443 is HTTPS, often needed for public sites. Therefore, D, 445, is the correct answer.
Play from 26:37 Question 24. Which port does RADIUS use for accounting records? Here are the options. Option A. 1813. Option B. 1812. Option C. 49. Option D. 88. Pause the video now if you want time to think about the answer.
The correct answer is A. 1813. RADIUS sends accounting data, such as session start and stop records, on UDP port 1813. Now, why are the other options incorrect? Option B is incorrect. Port 1812 is RADIUS authentication. Option C is incorrect. Port 49 is TACACS+. Option D is incorrect. Port 88 is Kerberos. Therefore, A, 1813, is the correct answer.
Play from 27:40 Question 25. A scan of an internet-facing web server shows TCP 3306 open. What is exposed? Here are the options. Option A. Microsoft SQL Server. Option B. A MySQL database. Option C. SMB file shares. Option D. Remote Desktop. Pause the video now if you want time to think about the answer.
The correct answer is B. A MySQL database. TCP 3306 is MySQL, and a database should not be reachable from the internet. Now, why are the other options incorrect? Option A is incorrect. Microsoft SQL Server uses 1433. Option C is incorrect. SMB uses 445. Option D is incorrect. Remote Desktop uses 3389. Therefore, B, A MySQL database, is the correct answer.
Play from 28:47 Question 26. A company wants DNS queries hidden inside normal encrypted web traffic. DNS over HTTPS uses which port? Here are the options. Option A. 853. Option B. 8443. Option C. 53. Option D. 443. Pause the video now if you want time to think about the answer.
The correct answer is D. 443. DNS over HTTPS sends queries as HTTPS requests, so it uses port 443 and blends in with web traffic. Now, why are the other options incorrect? Option A is incorrect. Port 853 is DNS over TLS. Option B is incorrect. Port 8443 is only an alternate HTTPS port. Option C is incorrect. Port 53 is plain DNS. Therefore, D, 443, is the correct answer.
Play from 30:07 Question 27. DNS lookups normally use UDP port 53. Which DNS activity is the classic reason to allow TCP port 53 as well? Here are the options. Option A. Zone transfers between DNS servers. Option B. Synchronizing clocks. Option C. Ordinary client name lookups. Option D. Handing out IP address leases. Pause the video now if you want time to think about the answer.
The correct answer is A. Zone transfers between DNS servers. Zone transfers copy whole zones between DNS servers and run over TCP 53. Now, why are the other options incorrect? Option B is incorrect. Clock sync is done by NTP. Option C is incorrect. Ordinary lookups normally use UDP. Option D is incorrect. Address leases come from DHCP. Therefore, A, Zone transfers between DNS servers, is the correct answer.
Play from 31:23 Question 28. A scan shows port 88 open on a server. What is the server most likely to be? Here are the options. Option A. A VoIP gateway. Option B. A web proxy. Option C. A Kerberos key distribution center, such as a domain controller. Option D. A database server. Pause the video now if you want time to think about the answer.
The correct answer is C. A Kerberos key distribution center, such as a domain controller. Port 88 is Kerberos, so the host is likely a domain controller acting as the KDC. Now, why are the other options incorrect? Option A is incorrect. VoIP gateways use SIP on 5060. Option B is incorrect. Web proxies often use 8080. Option D is incorrect. Databases use ports such as 1433 or 3306. Therefore, C, A Kerberos key distribution center, such as a domain controller, is the correct answer.
Play from 32:39 Question 29. Which service listens on TCP port 23 by default? Here are the options. Option A. DNS. Option B. SMTP. Option C. SSH. Option D. Telnet. Pause the video now if you want time to think about the answer.
The correct answer is D. Telnet. Telnet uses port 23 and sends usernames and passwords in cleartext, which is why SSH replaced it. Now, why are the other options incorrect? Option A is incorrect. DNS uses port 53. Option B is incorrect. SMTP uses port 25. Option C is incorrect. SSH uses port 22. Therefore, D, Telnet, is the correct answer.
Play from 33:39 Question 30. Attackers often brute-force this service when it is exposed to the internet, and it is a common ransomware entry point. Which port should be closed to the internet? Here are the options. Option A. 25 on a mail server. Option B. 443 on a public web server. Option C. 53 on a public DNS server. Option D. 3389. Pause the video now if you want time to think about the answer.
The correct answer is D. 3389. Exposed RDP on 3389 is a frequent target for password guessing and ransomware gangs; put it behind a VPN instead. Now, why are the other options incorrect? Option A is incorrect. Port 25 must stay open for a mail server to receive mail. Option B is incorrect. HTTPS on 443 must stay open for a public website. Option C is incorrect. Port 53 must stay open for a public DNS server. Therefore, D, 3389, is the correct answer.
Play from 34:59 Question 31. A public web server in the DMZ should accept only encrypted web traffic from the internet. Which inbound rule fits? Here are the options. Option A. Allow TCP 443 to the web server. Option B. Allow UDP 53 from any host to any host. Option C. Allow TCP 80 and TCP 23 to the web server. Option D. Allow TCP 3389 from the internet to the web server. Pause the video now if you want time to think about the answer.
The correct answer is A. Allow TCP 443 to the web server. Allowing only TCP 443 limits the server to HTTPS, following least privilege. Now, why are the other options incorrect? Option B is incorrect. An any-to-any DNS rule is far too broad. Option C is incorrect. Port 80 is unencrypted and Telnet on 23 should never be exposed. Option D is incorrect. Exposing RDP to the internet invites brute-force attacks. Therefore, A, Allow TCP 443 to the web server, is the correct answer.
Play from 36:29 Question 32. Which transport protocol does RADIUS normally use? Here are the options. Option A. UDP. Option B. ICMP. Option C. TCP. Option D. GRE. Pause the video now if you want time to think about the answer.
The correct answer is A. UDP. RADIUS runs over UDP, on ports 1812 and 1813. Now, why are the other options incorrect? Option B is incorrect. ICMP carries control messages such as ping. Option C is incorrect. TCP is what TACACS+ uses. Option D is incorrect. GRE is a tunneling protocol. Therefore, A, UDP, is the correct answer.
Play from 37:31 Question 33. An IPsec VPN must pass through a NAT device. Which port does NAT traversal use? Here are the options. Option A. TCP 1723. Option B. UDP 4500. Option C. UDP 500. Option D. UDP 1701. Pause the video now if you want time to think about the answer.
The correct answer is B. UDP 4500. NAT traversal wraps IPsec traffic in UDP 4500 so it survives address translation. Now, why are the other options incorrect? Option A is incorrect. TCP 1723 is PPTP. Option C is incorrect. UDP 500 is the initial IKE exchange. Option D is incorrect. UDP 1701 is L2TP. Therefore, B, UDP 4500, is the correct answer.
Play from 38:46 Question 34. Which port does DNS use? Here are the options. Option A. 53. Option B. 161. Option C. 67. Option D. 123. Pause the video now if you want time to think about the answer.
The correct answer is A. 53. DNS uses port 53, mostly over UDP for lookups. Now, why are the other options incorrect? Option B is incorrect. Port 161 is SNMP. Option C is incorrect. Port 67 is the DHCP server. Option D is incorrect. Port 123 is NTP. Therefore, A, 53, is the correct answer.
Play from 39:46 Question 35. Which port does FTPS use for its control channel in implicit TLS mode? Here are the options. Option A. 21. Option B. 22. Option C. 990. Option D. 989. Pause the video now if you want time to think about the answer.
The correct answer is C. 990. Implicit FTPS starts TLS immediately, with the control channel on port 990. Now, why are the other options incorrect? Option A is incorrect. Port 21 is plain FTP, or explicit FTPS that upgrades later. Option B is incorrect. Port 22 is SSH and SFTP. Option D is incorrect. Port 989 is the implicit FTPS data channel. Therefore, C, 990, is the correct answer.
Play from 40:54 Question 36. A help desk technician opens a full graphical session on a Windows workstation using Remote Desktop. Which port does this use by default? Here are the options. Option A. 22. Option B. 445. Option C. 5900. Option D. 3389. Pause the video now if you want time to think about the answer.
The correct answer is D. 3389. Microsoft Remote Desktop Protocol listens on port 3389. Now, why are the other options incorrect? Option A is incorrect. Port 22 is SSH, a command-line session. Option B is incorrect. Port 445 is SMB file sharing. Option C is incorrect. Port 5900 is VNC, a different remote desktop tool. Therefore, D, 3389, is the correct answer.
Play from 42:09 Question 37. Which port does SMTP use when one mail server relays email to another? Here are the options. Option A. 389. Option B. 110. Option C. 25. Option D. 143. Pause the video now if you want time to think about the answer.
The correct answer is C. 25. Server-to-server mail transfer with SMTP uses TCP port 25. Now, why are the other options incorrect? Option A is incorrect. Port 389 is LDAP, a directory service. Option B is incorrect. Port 110 is POP3, used to download mail. Option D is incorrect. Port 143 is IMAP, used to read mail. Therefore, C, 25, is the correct answer.
Play from 43:13 Question 38. Which port does POP3 over TLS use? Here are the options. Option A. 990. Option B. 993. Option C. 995. Option D. 110. Pause the video now if you want time to think about the answer.
The correct answer is C. 995. POP3S, the encrypted form of POP3, uses TCP port 995. Now, why are the other options incorrect? Option A is incorrect. Port 990 is FTPS. Option B is incorrect. Port 993 is IMAP over TLS. Option D is incorrect. Port 110 is plain POP3. Therefore, C, 995, is the correct answer.
Play from 44:19 Question 39. Which port does SMB file sharing use on modern Windows networks? Here are the options. Option A. 139. Option B. 3389. Option C. 2049. Option D. 445. Pause the video now if you want time to think about the answer.
The correct answer is D. 445. Modern SMB runs directly over TCP 445. Now, why are the other options incorrect? Option A is incorrect. Port 139 is the legacy NetBIOS session service. Option B is incorrect. Port 3389 is RDP. Option C is incorrect. Port 2049 is NFS. Therefore, D, 445, is the correct answer.
Play from 45:21 Question 40. Traffic to UDP port 161 on a router is most likely what? Here are the options. Option A. SNMP queries. Option B. NTP updates. Option C. Syslog messages. Option D. DNS lookups. Pause the video now if you want time to think about the answer.
The correct answer is A. SNMP queries. UDP 161 is where SNMP agents receive management queries. Now, why are the other options incorrect? Option B is incorrect. NTP uses 123. Option C is incorrect. Syslog uses 514. Option D is incorrect. DNS uses 53. Therefore, A, SNMP queries, is the correct answer.
Play from 46:27 Question 41. Which ports belong to the legacy NetBIOS services? Here are the options. Option A. 1812 and 1813. Option B. 137 through 139. Option C. 161 and 162. Option D. 445 only. Pause the video now if you want time to think about the answer.
The correct answer is B. 137 through 139. NetBIOS name, datagram and session services use ports 137, 138 and 139. Now, why are the other options incorrect? Option A is incorrect. Ports 1812 and 1813 are RADIUS. Option C is incorrect. Ports 161 and 162 are SNMP. Option D is incorrect. Port 445 is SMB directly over TCP. Therefore, B, 137 through 139, is the correct answer.
Play from 47:43 Question 42. An administrator needs encrypted command-line access to a Linux server. Which port should the firewall allow? Here are the options. Option A. 21. Option B. 3389. Option C. 22. Option D. 23. Pause the video now if you want time to think about the answer.
The correct answer is C. 22. SSH runs on TCP port 22 and encrypts the whole session, including the login. Now, why are the other options incorrect? Option A is incorrect. Port 21 is the FTP control channel, used for file transfer. Option B is incorrect. Port 3389 is RDP, a graphical Windows desktop, not a Linux shell. Option D is incorrect. Port 23 is Telnet, which sends everything in cleartext. Therefore, C, 22, is the correct answer.
Play from 48:55 Question 43. Network devices send unsolicited SNMP trap alerts to a manager. Which port does the manager listen on? Here are the options. Option A. 162. Option B. 6514. Option C. 161. Option D. 514. Pause the video now if you want time to think about the answer.
The correct answer is A. 162. SNMP traps are sent to the manager on UDP 162. Now, why are the other options incorrect? Option B is incorrect. Port 6514 is syslog over TLS. Option C is incorrect. Port 161 is where agents receive queries. Option D is incorrect. Port 514 is syslog. Therefore, A, 162, is the correct answer.
Play from 50:02 Question 44. A mail client sends outgoing messages to its provider, logs in, and upgrades the connection to encryption with STARTTLS. Which port is the standard choice for this? Here are the options. Option A. 993. Option B. 25. Option C. 587. Option D. 110. Pause the video now if you want time to think about the answer.
The correct answer is C. 587. Port 587 is the message submission port: the client authenticates and uses STARTTLS to encrypt the session. Now, why are the other options incorrect? Option A is incorrect. Port 993 is IMAPS, which retrieves mail. Option B is incorrect. Port 25 is mainly for relay between mail servers. Option D is incorrect. Port 110 is POP3, which retrieves mail. Therefore, C, 587, is the correct answer.
Play from 51:21 Question 45. A remote access VPN runs over TLS so it works from almost any hotel network. Which port does it most likely use? Here are the options. Option A. TCP 443. Option B. TCP 1723. Option C. UDP 500. Option D. UDP 1701. Pause the video now if you want time to think about the answer.
The correct answer is A. TCP 443. TLS VPNs use TCP 443, the same port as HTTPS, which is rarely blocked. Now, why are the other options incorrect? Option B is incorrect. TCP 1723 is PPTP. Option C is incorrect. UDP 500 is IKE for IPsec. Option D is incorrect. UDP 1701 is L2TP. Therefore, A, TCP 443, is the correct answer.
Play from 52:39 Question 46. A server is listening on TCP 8080. What is it most likely running? Here are the options. Option A. Syslog. Option B. An alternate HTTP web service or proxy. Option C. Secure Shell. Option D. Kerberos. Pause the video now if you want time to think about the answer.
The correct answer is B. An alternate HTTP web service or proxy. Port 8080 is a common alternate port for HTTP, often used by proxies and test web servers. Now, why are the other options incorrect? Option A is incorrect. Syslog uses port 514. Option C is incorrect. Secure Shell uses port 22. Option D is incorrect. Kerberos uses port 88. Therefore, B, An alternate HTTP web service or proxy, is the correct answer.
Play from 53:51 Question 47. Traffic arriving on UDP port 514 at a log server is most likely what? Here are the options. Option A. Syslog messages. Option B. NTP time updates. Option C. SNMP traps. Option D. TFTP file transfers. Pause the video now if you want time to think about the answer.
The correct answer is A. Syslog messages. UDP 514 is the default syslog port. Now, why are the other options incorrect? Option B is incorrect. NTP uses port 123. Option C is incorrect. SNMP traps use port 162. Option D is incorrect. TFTP uses port 69. Therefore, A, Syslog messages, is the correct answer.
Play from 54:55 Question 48. A security team wants every directory query encrypted with LDAP over TLS. Which port should they use? Here are the options. Option A. 389. Option B. 993. Option C. 443. Option D. 636. Pause the video now if you want time to think about the answer.
The correct answer is D. 636. LDAPS, which is LDAP over TLS, uses port 636. Now, why are the other options incorrect? Option A is incorrect. Port 389 is plain LDAP. Option B is incorrect. Port 993 is IMAP over TLS. Option C is incorrect. Port 443 is HTTPS. Therefore, D, 636, is the correct answer.
Play from 56:03 Question 49. Which file transfer protocol runs inside SSH on port 22? Here are the options. Option A. SFTP. Option B. TFTP. Option C. FTPS. Option D. FTP. Pause the video now if you want time to think about the answer.
The correct answer is A. SFTP. SFTP is a file transfer protocol carried by SSH, so it uses port 22 and is encrypted. Now, why are the other options incorrect? Option B is incorrect. TFTP uses UDP 69 with no security. Option C is incorrect. FTPS is FTP with TLS, on ports 21 or 990. Option D is incorrect. FTP uses ports 20 and 21 with no encryption. Therefore, A, SFTP, is the correct answer.
Play from 57:18 Question 50. Which pair correctly lists a plaintext port first and its TLS-protected port second? Here are the options. Option A. IMAP 143 and IMAPS 993. Option B. POP3 110 and POP3S 993. Option C. LDAP 389 and LDAPS 443. Option D. IMAP 143 and IMAPS 995. Pause the video now if you want time to think about the answer.
The correct answer is A. IMAP 143 and IMAPS 993. IMAP moves from 143 to 993 when it runs over TLS. Now, why are the other options incorrect? Option B is incorrect. 993 is IMAPS; POP3S is 995. Option C is incorrect. LDAPS uses 636, not 443. Option D is incorrect. 995 is POP3S, not IMAPS. Therefore, A, IMAP 143 and IMAPS 993, is the correct answer.
Play from 58:53 Question 51. In active mode FTP, which port does the server use for the data channel? Here are the options. Option A. 22. Option B. 990. Option C. 20. Option D. 21. Pause the video now if you want time to think about the answer.
The correct answer is C. 20. In active mode, the server sends data from port 20. Now, why are the other options incorrect? Option A is incorrect. Port 22 is SSH and SFTP. Option B is incorrect. Port 990 is FTPS. Option D is incorrect. Port 21 is the control channel. Therefore, C, 20, is the correct answer.
Play from 59:52 Question 52. A firewall log shows a user's browser sending traffic to a server on TCP port 80. What kind of traffic is this most likely to be? Here are the options. Option A. A DNS lookup. Option B. Encrypted HTTPS web traffic. Option C. Unencrypted HTTP web traffic. Option D. An SSH session. Pause the video now if you want time to think about the answer.
The correct answer is C. Unencrypted HTTP web traffic. Port 80 is the default for plain HTTP, so the content crosses the network unencrypted. Now, why are the other options incorrect? Option A is incorrect. DNS uses port 53. Option B is incorrect. HTTPS uses port 443. Option D is incorrect. SSH uses port 22. Therefore, C, Unencrypted HTTP web traffic, is the correct answer.
Play from 1:01:09 Question 53. Which secure protocol should replace Telnet for managing a network switch? Here are the options. Option A. HTTP. Option B. TFTP. Option C. SNMPv1. Option D. SSH. Pause the video now if you want time to think about the answer.
The correct answer is D. SSH. SSH gives the same command-line access as Telnet but encrypts the whole session. Now, why are the other options incorrect? Option A is incorrect. HTTP is unencrypted web traffic. Option B is incorrect. TFTP transfers files without security. Option C is incorrect. SNMPv1 is cleartext monitoring, not a shell. Therefore, D, SSH, is the correct answer.
Play from 1:02:14 Question 54. Which port does TFTP use? Here are the options. Option A. TCP 22. Option B. UDP 69. Option C. UDP 67. Option D. TCP 21. Pause the video now if you want time to think about the answer.
The correct answer is B. UDP 69. TFTP is a very simple file transfer protocol on UDP 69. Now, why are the other options incorrect? Option A is incorrect. TCP 22 is SSH. Option C is incorrect. UDP 67 is the DHCP server. Option D is incorrect. TCP 21 is FTP. Therefore, B, UDP 69, is the correct answer.
Play from 1:03:19 Question 55. Internal clients should resolve names only through the company's internal DNS server. Which outbound rule supports this? Here are the options. Option A. Allow port 53 to the internal DNS server only. Option B. Allow UDP 123 to any host. Option C. Allow TCP 389 to any host. Option D. Allow port 53 to any host on the internet. Pause the video now if you want time to think about the answer.
The correct answer is A. Allow port 53 to the internal DNS server only. Restricting port 53 to the approved DNS server stops clients from using outside resolvers that bypass company filtering. Now, why are the other options incorrect? Option B is incorrect. UDP 123 is NTP, not DNS. Option C is incorrect. TCP 389 is LDAP, not DNS. Option D is incorrect. Allowing 53 to anywhere lets clients bypass the company's DNS server. Therefore, A, Allow port 53 to the internal DNS server only, is the correct answer.
Play from 1:04:46 Question 56. Which port does IKE use to set up an IPsec VPN? Here are the options. Option A. UDP 1701. Option B. UDP 500. Option C. TCP 443. Option D. UDP 4500. Pause the video now if you want time to think about the answer.
The correct answer is B. UDP 500. IKE negotiates IPsec keys and security associations on UDP 500. Now, why are the other options incorrect? Option A is incorrect. UDP 1701 is L2TP. Option C is incorrect. TCP 443 is HTTPS, used by TLS VPNs. Option D is incorrect. UDP 4500 is used when NAT traversal is needed. Therefore, B, UDP 500, is the correct answer.
Play from 1:05:59 Question 57. A firewall must let IPsec ESP traffic through. What does the rule need to allow? Here are the options. Option A. UDP port 500 only. Option B. IP protocol number 50. Option C. TCP port 443. Option D. TCP port 50. Pause the video now if you want time to think about the answer.
The correct answer is B. IP protocol number 50. ESP is its own IP protocol, number 50, not a TCP or UDP port. Now, why are the other options incorrect? Option A is incorrect. UDP 500 handles only the IKE key exchange, not the encrypted data. Option C is incorrect. TCP 443 is HTTPS. Option D is incorrect. ESP does not run over TCP. Therefore, B, IP protocol number 50, is the correct answer.
Play from 1:07:15 Question 58. Which port does RADIUS use for authentication requests? Here are the options. Option A. 1812. Option B. 1813. Option C. 49. Option D. 389. Pause the video now if you want time to think about the answer.
The correct answer is A. 1812. RADIUS authentication runs on UDP port 1812. Now, why are the other options incorrect? Option B is incorrect. Port 1813 is RADIUS accounting. Option C is incorrect. Port 49 is TACACS+. Option D is incorrect. Port 389 is LDAP. Therefore, A, 1812, is the correct answer.
Play from 1:08:16 Question 59. Which port does HTTPS use by default? Here are the options. Option A. 443. Option B. 8080. Option C. 853. Option D. 80. Pause the video now if you want time to think about the answer.
The correct answer is A. 443. HTTPS is HTTP protected by TLS, and its default port is TCP 443. Now, why are the other options incorrect? Option B is incorrect. Port 8080 is a common alternate port for HTTP or proxies. Option C is incorrect. Port 853 is DNS over TLS. Option D is incorrect. Port 80 is plain, unencrypted HTTP. Therefore, A, 443, is the correct answer.
Play from 1:09:26 Question 60. Which port does VNC use by default? Here are the options. Option A. 5060. Option B. 3389. Option C. 5900. Option D. 22. Pause the video now if you want time to think about the answer.
The correct answer is C. 5900. VNC remote desktop listens on TCP 5900. Now, why are the other options incorrect? Option A is incorrect. Port 5060 is SIP. Option B is incorrect. Port 3389 is Microsoft RDP. Option D is incorrect. Port 22 is SSH. Therefore, C, 5900, is the correct answer.
Play from 1:10:32 Question 61. Which set of ports carries only encrypted traffic by default? Here are the options. Option A. 21, 22 and 443. Option B. 80, 993 and 995. Option C. 23, 443 and 636. Option D. 22, 443 and 993. Pause the video now if you want time to think about the answer.
The correct answer is D. 22, 443 and 993. SSH on 22, HTTPS on 443 and IMAPS on 993 are all encrypted. Now, why are the other options incorrect? Option A is incorrect. Port 21 is cleartext FTP. Option B is incorrect. Port 80 is cleartext HTTP. Option C is incorrect. Port 23 is cleartext Telnet. Therefore, D, 22, 443 and 993, is the correct answer.
Play from 1:11:50 Question 62. Which of these ports is used to read or retrieve mail, not to send it? Here are the options. Option A. 465. Option B. 143. Option C. 587. Option D. 25. Pause the video now if you want time to think about the answer.
The correct answer is B. 143. Port 143 is IMAP, which reads mail from the server. Now, why are the other options incorrect? Option A is incorrect. Port 465 is SMTP over implicit TLS. Option C is incorrect. Port 587 is SMTP submission. Option D is incorrect. Port 25 is SMTP relay. Therefore, B, 143, is the correct answer.
Play from 1:12:52 Question 63. A scan finds TCP 445 open on a laptop. Which service is listening? Here are the options. Option A. LDAP. Option B. SMB. Option C. RDP. Option D. HTTPS. Pause the video now if you want time to think about the answer.
The correct answer is B. SMB. TCP 445 is the SMB file and printer sharing service. Now, why are the other options incorrect? Option A is incorrect. LDAP uses 389. Option C is incorrect. RDP uses 3389. Option D is incorrect. HTTPS uses 443. Therefore, B, SMB, is the correct answer.
Play from 1:13:55 Question 64. Which port does DNS over TLS use? Here are the options. Option A. 636. Option B. 53. Option C. 853. Option D. 443. Pause the video now if you want time to think about the answer.
The correct answer is C. 853. DNS over TLS has its own port, TCP 853. Now, why are the other options incorrect? Option A is incorrect. Port 636 is LDAP over TLS. Option B is incorrect. Port 53 is ordinary unencrypted DNS. Option D is incorrect. Port 443 is used by DNS over HTTPS, a different method. Therefore, C, 853, is the correct answer.
Play from 1:15:00 Question 65. Which SNMP version adds authentication and encryption? Here are the options. Option A. SNMPv3. Option B. SNMP with the public community string. Option C. SNMPv1. Option D. SNMPv2c. Pause the video now if you want time to think about the answer.
The correct answer is A. SNMPv3. SNMPv3 adds user authentication and encryption, which earlier versions lack. Now, why are the other options incorrect? Option B is incorrect. The public community string is a well-known default and is not secure. Option C is incorrect. SNMPv1 uses cleartext community strings. Option D is incorrect. SNMPv2c also uses cleartext community strings. Therefore, A, SNMPv3, is the correct answer.
Play from 1:16:12 Question 66. An administrator wants log messages encrypted on their way to the SIEM. Which port is standard for syslog over TLS? Here are the options. Option A. 636. Option B. 514. Option C. 162. Option D. 6514. Pause the video now if you want time to think about the answer.
The correct answer is D. 6514. Syslog over TLS uses TCP 6514. Now, why are the other options incorrect? Option A is incorrect. Port 636 is LDAP over TLS. Option B is incorrect. Port 514 is plain syslog. Option C is incorrect. Port 162 is for SNMP traps. Therefore, D, 6514, is the correct answer.
Play from 1:17:24 Question 67. Which port is used for SMTP submission over implicit TLS, where encryption starts the moment the connection opens? Here are the options. Option A. 636. Option B. 465. Option C. 995. Option D. 587. Pause the video now if you want time to think about the answer.
The correct answer is B. 465. Port 465 carries SMTP with implicit TLS, so the session is encrypted from the first packet. Now, why are the other options incorrect? Option A is incorrect. Port 636 is LDAP over TLS. Option C is incorrect. Port 995 is POP3 over TLS. Option D is incorrect. Port 587 starts in plaintext and upgrades with STARTTLS. Therefore, B, 465, is the correct answer.
Play from 1:18:38 Question 68. Kerberos logins start failing across a domain because the server clocks have drifted apart. Which protocol and port keep the clocks in sync? Here are the options. Option A. DHCP on UDP 67. Option B. NTP on UDP 123. Option C. Syslog on UDP 514. Option D. SNMP on UDP 161. Pause the video now if you want time to think about the answer.
The correct answer is B. NTP on UDP 123. Kerberos rejects tickets when clocks differ too much, and NTP on UDP 123 keeps them aligned. Now, why are the other options incorrect? Option A is incorrect. DHCP hands out IP addresses. Option C is incorrect. Syslog collects log messages. Option D is incorrect. SNMP monitors and manages devices. Therefore, B, NTP on UDP 123, is the correct answer.
Play from 1:19:58 Question 69. Which port does Kerberos authentication use? Here are the options. Option A. 389. Option B. 1812. Option C. 88. Option D. 49. Pause the video now if you want time to think about the answer.
The correct answer is C. 88. Kerberos clients reach the key distribution center on port 88. Now, why are the other options incorrect? Option A is incorrect. Port 389 is LDAP. Option B is incorrect. Port 1812 is RADIUS authentication. Option D is incorrect. Port 49 is TACACS+. Therefore, C, 88, is the correct answer.
Play from 1:20:57 Question 70. An auditor wants a list of open ports that all carry cleartext logins. Which set fits? Here are the options. Option A. 22, 990 and 6514. Option B. 443, 993 and 995. Option C. 21, 23 and 80. Option D. 22, 443 and 636. Pause the video now if you want time to think about the answer.
The correct answer is C. 21, 23 and 80. FTP on 21, Telnet on 23 and HTTP on 80 all send credentials unencrypted. Now, why are the other options incorrect? Option A is incorrect. SSH, FTPS and syslog over TLS are all encrypted. Option B is incorrect. HTTPS, IMAPS and POP3S are all encrypted. Option D is incorrect. SSH, HTTPS and LDAPS are all encrypted. Therefore, C, 21, 23 and 80, is the correct answer.
Play from 1:22:25 Question 71. Which port does IMAP use without encryption? Here are the options. Option A. 25. Option B. 143. Option C. 110. Option D. 993. Pause the video now if you want time to think about the answer.
The correct answer is B. 143. Plain IMAP uses TCP 143. Now, why are the other options incorrect? Option A is incorrect. Port 25 is SMTP. Option C is incorrect. Port 110 is POP3. Option D is incorrect. Port 993 is IMAP over TLS. Therefore, B, 143, is the correct answer.
Play from 1:23:28 Question 72. Which port does SIP over TLS use? Here are the options. Option A. 5061. Option B. 5060. Option C. 993. Option D. 443. Pause the video now if you want time to think about the answer.
The correct answer is A. 5061. Encrypted SIP signaling uses TCP 5061. Now, why are the other options incorrect? Option B is incorrect. Port 5060 is unencrypted SIP. Option C is incorrect. Port 993 is IMAP over TLS. Option D is incorrect. Port 443 is HTTPS. Therefore, A, 5061, is the correct answer.
Play from 1:24:35 Question 73. A user's mail client downloads messages with POP3 and no encryption. Which port is in use? Here are the options. Option A. 143. Option B. 25. Option C. 995. Option D. 110. Pause the video now if you want time to think about the answer.
The correct answer is D. 110. Plain POP3 uses TCP port 110. Now, why are the other options incorrect? Option A is incorrect. Port 143 is plain IMAP. Option B is incorrect. Port 25 is SMTP, used for sending. Option C is incorrect. Port 995 is POP3 over TLS, which is encrypted. Therefore, D, 110, is the correct answer.
Play from 1:25:42 Question 74. A PC boots from the network with PXE and downloads its boot image over UDP port 69. Which protocol is it using? Here are the options. Option A. SFTP. Option B. TFTP. Option C. FTP. Option D. HTTP. Pause the video now if you want time to think about the answer.
The correct answer is B. TFTP. PXE network boot commonly pulls the boot file with TFTP on UDP 69. Now, why are the other options incorrect? Option A is incorrect. SFTP uses TCP 22. Option C is incorrect. FTP uses TCP 20 and 21. Option D is incorrect. HTTP uses TCP 80. Therefore, B, TFTP, is the correct answer.
Play from 1:26:58 Question 75. Which ports does DHCP use? Here are the options. Option A. UDP 67 and 68. Option B. UDP 53. Option C. UDP 123. Option D. UDP 161 and 162. Pause the video now if you want time to think about the answer.
The correct answer is A. UDP 67 and 68. DHCP servers listen on UDP 67 and clients use UDP 68. Now, why are the other options incorrect? Option B is incorrect. UDP 53 is DNS. Option C is incorrect. UDP 123 is NTP. Option D is incorrect. UDP 161 and 162 are SNMP. Therefore, A, UDP 67 and 68, is the correct answer.
