Recurring ICMP Bad Checksum Warning

[Chuck Swiger]

On Jul 14, 2011, at 5:18 AM, monarci wrote:
> I am currently running a company's FreeBSD web server and I am constantly
> receiving the ICMP Bad Checksum warning.  

You most likely have a NIC with hardware checksum capabilities; tcpdump sees outgoing packets before the hardware generates the checksums.  You can double-check by sniffing the traffic from a laptop connected to a monitoring port of the switch, or put a hub in place for testing so that the laptop also receives the traffic.

Regards,
-- 
-Chuck