ipfw nat and localy initiated UDP traffic (bad udp cksum)

[Chuck Swiger]

On Jul 16, 2009, at 12:19 PM, Dmitriy Demidov wrote:
> Update about this issue.
> There is somthing wrong with UDP pass through - ipfw nat makes it  
> "bad cksum".

tcpdump receives local network traffic before the checksums are  
computed (especially if hardware checksums are enabled); this is a non- 
issue, although you could confirm by sniffing the traffic from an  
external machine like a laptop.

Regards,
-- 
-Chuck