Using Extended Access Control List, we can filter traffic based on TCP and UDP port numbers or port names. Click the following link to know important TCP port numbers. You can specify a name also for port numbers.

For example, you can use the keyword smtp to match SMTP traffic (port number 25).

Common TCP Port Names

 

Port Name	Keyword
FTP Data (TCP port number 20)	ftp-data
FTP Control (TCP port number 21 )	ftp
Telnet (TCP port number 23)	telnet
SMTP (TCP port number 25)	smtp
HTTP (TCP port number 80)	www

 

Common UDP Port Names

 

Port Name	Keyword
DNS (UDP port number 53)	dns
TFTP (UDP port number 69)	tftp
SNMP (UDP port number 161)	snmp
IP RIP (UDP port number 520)	rip

 

Related Topics...

• Introduction to Access Control Lists (ACL)

• Standard Access Control Lists (ACLs)

• Where should a Standard Access Control List (ACL) be placed

• Access Control List (ACL) - Wildcard Masks

• How to create and configure Standard Access Control Lists (ACLs)

• Extended Access Control Lists (ACLs)

• Where should an Extended Access Control List (ACL) be placed

• Extended Access Control List (ACL) - Operators

• Extended Access Control List (ACL)- established Keyword

• How to create and configure Extended Access Control Lists (ACLs)

• How to create and configure Access Control Lists (ACLs) for vty lines (telnet and ssh)

• Named Access Control Lists (ACLs)

• How to create and configure Standard Named Access Control Lists (ACLs)

• How to create and configure Extended Named Access Control List (ACL)

• How to edit a Named Access Control List (ACL) on router