Linux network behavior wierdness

[Dave Johnson]

Paul Lussier writes:
> 
> Hi all,
> 
> I have a wierd problem where some hosts respond to a broadcast ping
> packet and others don't.
> 
> I have some hosts which, when I do a ping -b 10.95.0.0 everything answers.
> On other hosts, doing exactly the same thing, I get no response.
> 
> A reboot resets a "broken" host, but over time it will re-develop the problem.
> And I can't seem to figure out how to make the problem occur...
> 
> I can't figure out if it's something we're doing which is causing this
> change, or if it's a kernel thing where some threshold is reached and
> it just stops.
> 
> Fwiw, we're running Debian/Etch with a 2.6.18 kernel.  Most NICs are
> Intel e1000, though some are broadcom.  In general, I've seen it
> happen across our lab on different hardware platforms with different
> motherboards and nics.
> 
> Any insights would be most appreciated.

10.95.0.0 is an unusual broadcast address, how did you end up with
that?

Watch out for /proc/sys/net/ipv4/icmp_echo_ignore_broadcasts.  The
default was changed between 2.6.13 and 2.6.14 to ignore by default.

-- 
Dave