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New Member

Seeing private IPs on outside of Cisco ASA

We're working with a Cisco ASA 5520 with older 8.2 code and in doing a sniff, I'm seeing some private IP's coming through the ASA and trying to get out.  Some of them to public IP's and some to private IP's such as   As the ASA is setup with NAT and working, i would have thought if it was a simple access list issue, I wouldn't see the private ip of the internal host?  What could be cause it not to show up as the global ip or nat?  In fact, netbios was shown on the outside as well so you could see the device's name.  It couldn't get anywhere, but you could still see it. Any ideas?

Hall of Fame Super Silver

A NAT exemption would cause

A NAT exemption would cause such an issue. There are other ways but that's the most likely one. 

The easiest and most accurate way to see why the packets are going through is to run packet-tracer to see if/how the ASA should be passing the traffic.

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