help with fast nat

Taylor Grant gtaylor at
Thu Apr 14 02:25:26 CEST 2005

What system is doing the pinging (IP / subnet) and what is it pining (IP / subnet)?

> [root at dorm-test ~]# ip route add via

If you were pinging passing through this router where 10.0.31.x/24 was on a different subnet and you told this router that was accessible via (the system doing the ping) you just told the router to loop the traffic back on the system doing the pinging.

> [root at dorm-test ~]# ip rule add from nat

I'm not sure what you are hoping to accomplish by doing this.  This will make any traffic coming from (the system doing the pinging?) appear as if it is coming from which would cause the router to send the traffic back to the 10.0.31.x/24 network.

I have a feeling what you might have done (if I understand what you have written here correctly) is effectively do a double loop back as in the system's traffic loops back on it's self at the router as does the system's traffic loop back on it's self at the router too.

There really is not enough information to try to help you, but based on what I have seen this is what I deduce.  I hope that will help you in some way.

Grant. . . .

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