I have been looking for an example online but could not find one so hopefully someone here might give me an example. I am trying to set up an ACL to block any entire network accessing a specific device on another network. The routing protocol I am using is ospf. I was trying something like this but it doesnt work.

access-list 106 deny ospf host Server
access-list 106 permit ip any any
int g0/0
ip access-group 106 in

If anyone can provide an example I would be grateful.

  • Did any answer help you? if so, you should accept the answer so that the question doesn't keep popping up forever, looking for an answer. Alternatively, you could provide and accept your own answer.
    – Ron Maupin
    Aug 10, 2017 at 23:13

2 Answers 2


You are confusing routing with traffic flow. The routing protocol is used to learn networks from other routers. It does not directly affect the flow of traffic. If you want to block access to the host Server from, you want to block IP packets. So your access list would look something like this;

access-list 106 deny ip host Server
access-list 106 permit ip any any

You want to deny IP packets from that network. Update the first line of your ACL to read access-list 106 deny ip host Server and you should be good.

The fact that OSPF is your dynamic routing protocol has no impact on this question, it's just extra information that is throwing you off.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.