Extended IP Access Control List and Configuration.

Extended IP Access Control List

RouterA(config)#access-list 103 remark stop telnet to router A whose source ip 1.1.1.2

RouterA(config)#access-list 103 deny tcp host 1.1.1.2 host 1.1.1.2 eq 23

RouterA(config)#access-list 103 permit ip any

RouterA(config)#int s0/0

RouterA(config-if)#ip access-group 103 in

RouterA#show access-lists

Extended ip access list 103

Deny tcp host 1.1.1.2 host 1.1.1.1 eq telnet(2 matches)

Permit ip any (160 matches)

Standard IP Access Control List.

RouterA#configure terminal

RouterA(config)#access-list 1 remark stop all traffic whose source ip 1.1.1.2

RouterA(config)#access-list 1 deny 1.1.1.2 0.0.0.0

RouterA(config)#access-list 1 permit any

RouterA(config)#int s0/0

RouterA(config-if)#ip access-group 1 in

RouterA#show access-lists

Standard IP access list 1

Deny 1.1.1.2

Permit any

Now verify these configuration on router with command us under:

RouterA#show ip int s0/0

RouterB#ping