Definition of "eq"

drklutz

I am very new to CCNA studying. But I understand a lot already from experience in networking and Microsoft. Can someone define what "eq" is for in access list syntax?

Thanks very much.

Bl8ckr0uter

EQ = Equal. Usually followed by a port.

Ex:

Extended IP access list EXAMPLE
    10 permit tcp host 1.1.1.1 host 1.1.1.2 eq 123

This will allow tcp traffic from host 1.1.1.1 to host 1.1.1.2 only if it is on port 123.

onesaint

Bl8ckr0uter wrote: »

EQ = Equal. Usually followed by a port.

Ex:

Extended IP access list EXAMPLE
    10 permit tcp host 1.1.1.1 host 1.1.1.2 eq 123

This will allow tcp traffic from host 1.1.1.1 to host 1.1.1.2 only if it is on port 123.

To add to this, there are qualifiers that can filter ports at the end of an extended ACL. They are:

"eq" Match only packets on a given port number

"established" For an established connection

"gt" Match only packets with a greater port number

"lt" Match only packets with a lower port number

"neq" Match only packets not on a given port number

"precedence" Match packets with given precedence value

"range" Match only packets in the range of port numbers

You can find these with a "?" after the destination IP while writing your ACL. This link may be helpful.