[c-nsp] DHCP Problem with Cisco Phones

[Mark Borchers]

Seeing the following problem on a two-node WAN:

Cisco phones are configured to obtain ip address via dhcp
from local router.  DHCP bindings on router show address
assigned, but the phone never appears to "receive" the
address and cannot be pinged.

Call Manager/TFTP server on opposite end of WAN has some
intermittent log entries corresponding to addresses in
dhcp bindings table.

We have implemented this architecture numerous times in
the past.  The only difference in this case is the presence
of a GRE tunnel on the WAN link.  We speculated about an
MTU issue due to the tunnel, but do not believe TFTP packets
are big enough to make this a factor.

Any insight appreciated,

--
Mark Borchers
IGI, LLC