I have come across a scenario that I have been searching for some reference material.
An access-group is applied to an interface(in), but there is no access-list configured.
On one side, someone has mentioned to me that the access-list is implied and that a deny all would occur. The interface has both inbound and outbound traffic. Thus I do not believe this answer.
On the other side it looks as if there was an access-list configured on the router and then was removed without removing the access-group. Thus negating the access-group to a non-functioning entry in the router configuration.
Can anyone please point me in the right direction. "gut" feeling leans me towards the access-group being a non-functioning entity.
I believe this depends on what level of IOS you are running. Older IOS would use the implicit deny as the default for a missing access list so all traffic would be denied leading to the potential to lock yourself out quite easily when doing changes remotely.
However, this was changed at some point to allow all traffic.
I will start my digging for the change point over the weekend. It sticks in my mind that I have read something about it but need to find it so I can take it out of the "questions to answer" side of things. Thanks for your time.
Table of ContentsIntroductionVersion HistoryPossible Future
UpdatesDocuments PurposeNAT Operation in ASA 8.3+ SectionsRule Types
Network Object NATTwice NAT / Manual NATRule Types used per SectionNAT
Types used with Twice NAT / Manual NAT and Network Obje...
Table of Contents Introduction:This document describes details on how
NAT-T works. Background: ESP encrypts all critical information,
encapsulating the entire inner TCP/UDP datagram within an ESP header.
ESP is an IP protocol in the same sense that TCP an...