Do you have recir enabled ? If not, good one to enable and check for
status of issue.
http://www.cisco.com/en/US/docs/ios/mpls/command/reference/mp_m1.html#wp1012208
"If you do not enable tunnel-MPLS recirculation, the IPv4 and
IPv4-tunneled packets that need to be labeled (for example, the packets
that are encapsulated with an MPLS header) will be corrupted when they
are transmitted from the Cisco 7600 series router."
Shimol
On 11/4/10 4:00 PM, Rettke, Brian wrote:
Beginning work on our implementation of MPLS for the backbone network. I've run
into difficulty with our GRE tunnels. The GRE Tunnel sits on our co-lo router
(a Cisco 7600), and it uses a route-map to push our 10.x modem traffic to our
DHCP servers. This is because the backbone is not complete and DHCP traffic
needs to traverse the internet. What I have found is that when I enable basic
MPLS on the co-location interfaces that head back to the individual systems,
DHCP traffic still works, but ICMP and other 10.x traffic dies. There is also
an intermittent problem with DHCP when it is enabled, where not all DISCOVERS
are answered. I've tried everything I can think of, including adjusting MTU and
TCP MSS. It only seems to impact when the co-location router has a GRE tunnel
on one buffer, which it terminates, and then it has to encapsulate traffic with
an MPLS tag before sending out of the other buffer. Theoretically, it should
work, but I can't figure out if there is some prob
lem with MPLS' interaction with the tunnel. Has anyone encountered something
similar?
Sincerely,
Brian A . Rettke
RHCT, CCDP, CCNP, CCIP
Network Engineer, CableONE Internet Services
