PING utility generates an invalid checksum in the IP header when an odd
packet size is specified. It appears through testing that the contents
of the data buffer cause the intermittant operation. When the start of
the buffer begins with 0x00 the checksum error does not manifest. The
data at the start of the buffer appears random in all tested linux version
(5.2, 6.0, and 6.1) and this in turn appears to be the cause of the
We have found this same bug in other PING utilities and router code.
Verification used an external network sniffer as well as other network
clients, including PING under Win98 (yech!) which worked correctly.
I realize this is not a RED HAT component, but I cannot find the OSF
individual responsible for this component, and Im daunted by the prospect
of installing the sources and digging to find it. If you or someone else
will send the source file I'll gladly fix it for ya!
Best regards, Bob Kennett
What version of netkit-base are you using? (try rpm -qf /bin/ping)
A problem with broken checksums on odd length packates was fixed in June
------- Email From Robert Kennett <rkennett> 12/10/99 15:54 -------
Attached to Bug # 7739.
Try the netkit-base-0.10-37 from Red Hat 6.1. That should fix the
odd len checksum problem and a few other persnickety bugs. However,
watchout for the changed semantics of -c (use -w instead).
Please reopen this bug if netkit-base-0.10-37 does not fix your