As the title suggests, I want to have a limited access to my router through telnet. I want only specific networks to be able to telnet my router. All others should be blocked from telnetting the router.

So let’s start:

Enter global config mode

Certhacker#configure terminal
Enter configuration lines, one per line. End with CNTL/Z
Certhacker(config)#

Create Access list to permit a network

Certhacker(config)#access-list 20 permit 192.168.1.0 0.0.0.255

This will create an access list no. 20 which will permit the network 192.168.1.0/24. Now we need to apply this access list to a vty line.

Apply access list to router’s virtual terminals

Certhacker(config)#line vty 0 4
Certhacker(config)#access-class 20 in

Now see the access list applied

Certhacker#show access-list

This will show the recently applied access list 20. Please note that there is an implied deny all at the end of each access list that will deny all other networks other than the permitted ones.

Try this tutorial live on the following simulation lab:

CCNA Simulation Lab Access List Tutorial