topic Firewall ACL bypass doubt in Network Security

Firewall ACL bypass doubt

oldcreek12 — Mon, 11 Mar 2019 21:49:21 GMT

Hi, all,

I have a doubt about firewall interface ACL bypass, I understand stand that when traffic is initiated from inside to an outside server, the firewall will create a flow entry and bypass ACL check on outside interface, how about the other way around? if the traffic is initated from outside (traffic explicitly allowed on outside ACL), but inside access-list is not explicitly allowing this traffic, will the connection be established?

Firewall ACL bypass doubt

acomiskey — Fri, 11 Nov 2011 19:57:17 GMT

Yes it would be allowed.

Firewall ACL bypass doubt

oldcreek12 — Fri, 11 Nov 2011 20:09:38 GMT

Thanks, that is what I thought so, I have inside ACL did not explict allow traffic to remote access SSL-VPN address pool, since remote-access VPN traffic is always initiated from client, this worked fine. But we are having strange behavior when Cisco Desktop Agent is running on SSL VPN client laptop, the agent can not see other agents, I suspected that CDA is using some ports that are not recognized to ASA, so I added inside ACL to explictly allow any IP traffic to remote SSL-VPN address pool IPs, that fixed the problem.