dhcpd sends ICMP echo requests to addresses outside of defined ranges?

Frank Stanek frank.stanek at est.fujitsu.com
Thu Apr 22 13:07:07 UTC 2010


I'm getting a rather strange effect that seems to
contradict what's written in the manual page. I tried
to research this online but couldn't really find
anything except for one person who claimed that dhcpd
sometimes falsely picks up echo replies not intended
for it, which I kind of doubt.
The dhcpd version is dhcp-server-3.0.3-23.55 on SLES10SP2.

I'm seeing a lot of log entries like this:
Apr 22 08:15:44 infrahost01 dhcpd: unexpected ICMP Echo Reply from

Now this wouldn't be strange if that address were in
our range definitions. Our only range in dhcpd.conf is
subnet netmask {
This is not a failover setup.

The host does exist, it is a statically
configured server. I also see the same message for a
some other static hosts in other subnets, also not part
of our defined range.

The manual page says this however:
> The DHCP server checks IP addresses to see if they
> are in use before allocating them to clients. [...]
> This is only done for leases that have been specified
> in range  statements, and only when the lease is
> thought by the DHCP server to be free

That should not be the case here? Does anyone have an
explanation for this? I'm kind of suspecting a configuration
error on my part.


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