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Double inspection on Cisco ASA FW

I have a Cisco ASA 5510 firewall which i have access lists on the inbound interface, and also on the outbound interface.

How does inspection apply to this? Will it make any trouble ? Double inspection?

I do this because I think more security

(inside network) ---> (inbound acl) [inside-FW-outside] (oubbound acl) --> internet


KimYin Wu

Super Bronze

Double inspection on Cisco ASA FW


I would personally suggest using an Outboud and Inbound ACL on the same interface of the ASA unless there is a very specific need for it.

You might end up complicating the setup in the long run and not necesarily gaining anything in return.

In your above decribed situation the traffic would match the Inbound ACL on the "inside" interface and the Outbound ACL on the "outside" interface. Though naturally in these ACLs the source address is different as the ASA probably does NAT for the source in between?

Hope this helps

Please do remember to mark a reply as the correct answer if it answered your question.

Feel free to ask more if needed

- Jouni