effect of implict acls with no explicit inside_in

[lcaruso]

Hi,

Recently I came across an ASA that had no inside_in acl explicitly defined. When I defined one, I was surprised to learn it may have became an issue, but I backed the change out so quickly I was not able to verify.

At any rate, what is the effect of not having an explict inside_in acl? What effect do the implict acls have in either case?

Thanks.

[Collin Clark · Accepted solution]

An ACL is not required when going from a higher security interface to a lower one. It certinaly is good practive to have an ACL in with an explicit deny. When going the other way there is an implicit deny even if there is not an ACL.