PIX 515 static problems

Unanswered Question
May 11th, 2007
User Badges:


I've got a question about static mappings on a PIX515E running OS 6.3(5).

My scenario:

There are two inside LANs attached to the PIX each of which have a static mapping to the outside interface for the whole subnet.

eg static (inside,outside) netmask

In addition, because access to a couple of servers on the internal LANS is required i've allocated these a public address:

eg static (inside,outside) netmask

I took it that the more specific static entry (for the public address) would override the static mapping that already exists for the whole LAN.

Is this the case? When connecting from the outside inbound the xlate entry is created because the destination address is the public IP. However connnections initiated from the inside are translated to the 10. address rather than the public IP.

This is not a problem as the setup is designed for external connections in. However I am curious about this behaviour - is the order of the static statements in the config important?

This has been bugging me an a couple of colleagues for a while - would be v grateful for any ideas?!


  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 0 (0 ratings)
vitripat Fri, 05/11/2007 - 06:01
User Badges:
  • Gold, 750 points or more

Static nat commands are matched in order and are not based on most specific entry. Please refer to following link-


Here is an example-

If you have following static entries in order:

static (inside,outside) netmask 0 0

static (inside,outside) netmask 0 0

If someone from outside initiates connection to host, it will be translated to and reply will go accordingly. If someone initiates connections to, the reply will follow first static because it comes first in order.

I hope this clears things for you.



PDEdwards Fri, 05/11/2007 - 07:00
User Badges:

Many thanks Vibhor - didn't realise the order was important.




This Discussion