Server down in case of configuring access-list for protecting worms
I find a strange situation.
In the router, when I configure the access-list for protecting worm port like followings. If I configure these access-lists, servers connected to this router is well operating. But, when I delete access-list configuration, servers will be downed. What is the cause ?
Re: Server down in case of configuring access-list for protectin
Actually it has not been true for a long time that if you have access lists defined, have access-group applied to interface, and then remove the access list that you lose connectivity because of the implicit deny any at the end of the access list. At one point in time that was the behavior of IOS, but it has not worked that way for a very long time. The behavior now is that if you remove the access list it acts like there is a permit any.
Edwin's point about not seeing any permit in the access list is well taken. If an access list has a number of deny statements and no permit statements, then I would expect to lose connectivity since everything would be denied.
So the behavior described is the reverse of the behavior that I would expect. I am not sure how to explain this.
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