dhcpd not receiving DHCPRELEASE and not freeng leases

[Peter Rathlev]

> On Thu, Jun 14, 2012 at 11:29 AM, <e.erofeev at tr.center.rt.ru> wrote:
...
> > No firewall rules blocking traffic:
> > # iptables -nvL
> > Chain INPUT (policy ACCEPT 6455 packets, 945K bytes)
> >  pkts bytes target     prot opt in     out  source    destination
> >     0     0 ACCEPT     all  --  lo     *    0.0.0.0/0 0.0.0.0/0
> > 99037   68M ACCEPT     all  --  *      *    0.0.0.0/0 0.0.0.0/0    state RELATED,ESTABLISHED

On Thu, 2012-06-14 at 18:10 +1000, Glenn Satchell wrote:
> Are there any lines in syslog showing packets that are blocked by
> iptables? My guess is that the RELATED iptables rule may not apply to the
> dhcprelease that comes along later. In fact I can't see how the initial
> dhcpdiscover gets through the firewall. Perhaps addin
> g a rule to allow
> traffic in on eth2 with a destination of 67/udp?

If the above shown iptables rules are complete they should allow
everything. There's an ACCEPT policy, so nothing is blocked.

As for the problem itself: Our servers (4.2.4) have no problems
receiving RELEASE messages and update their lease files. We mostly
receive them from Windows clients of course.

Maybe the RELEASE message is malformed somehow. If so, then maybe adding
the "-v -v" flags to tcpdump might shed some light.

-- 
Peter