I'm studying a "good practices" document for Cisco IOS, and one of its controls tells me to disable ICMP Redirect packets in the router. Sounds reasonable. So I go test it in Cisco Packet Tracker (a nifty little network emulator program). In my virtual router's IOS CLI, I type the following:
jcios01#config term
Enter configuration commands, one per line. End with CNTL/Z.
jcios01(config)#interface GigabitEthernet9/0
jcios01(config-if)#no ip mask-reply
^
% Invalid input detected at '^' marker.
I'm puzzled. That's what the document told to do. enable, "config term", "interface " and then "no ip mask-reply". Am I forgetting something?
Yes, I'm a Cisco newbie.