[afnog] Problem bringing up MPLS on disimilar interfaces

[Frank A. Kuse]

Below are the requested parameters.


The show mpls ldp neighbor doesn't show anything.

 

 

Cisco 7200 NPE 400

 

interface Loopback0

 ip address 212.85.211.131 255.255.255.255

 ip router isis

 

interface FastEthernet0/0

 description Interface to P routers

 ip address 212.85.212.3 255.255.255.248

 duplex auto

 speed auto

 mpls label protocol ldp

 mpls ip

 mpls mtu 1512

 

router isis

 net 49.0001.0000.0000.0300.00

 redistribute static ip

 passive-interface default

 no passive-interface FastEthernet0/0

 no passive-interface FastEthernet0/1

 no passive-interface FastEthernet2/0

 no passive-interface FastEthernet2/1

 no passive-interface Loopback0

 

Cisco 7200 NPE G1

 

 

interface Loopback0

 ip address 212.85.211.130 255.255.255.255

 ip router isis 

!

interface GigabitEthernet0/1

 description Interface to POPs

 mtu 1512 

 ip address 212.85.212.2 255.255.255.248

 duplex auto

 speed auto

 media-type rj45

 negotiation auto

 mpls label protocol ldp

 mpls ip

 

router isis 

 net 49.0001.0000.0000.0200.00

 passive-interface default

 no passive-interface GigabitEthernet0/1

 no passive-interface GigabitEthernet0/2

 no passive-interface GigabitEthernet0/3

 no passive-interface Loopback0

 

-----Original Message-----
From: Mark Tinka [mailto:mtinka at globaltransit.net] 
Sent: Saturday, September 20, 2008 11:55 AM
To: Frank A. Kuse
Cc: afnog at afnog.org
Subject: Re: [afnog] Problem bringing up MPLS on disimilar interfaces

On Saturday 20 September 2008 03:08:31 Frank A. Kuse wrote:

> I am having some trouble bringing up MPLS up on disimilar interfaces ( 
> FastEthernet Interface and Gigabit interface both connecting to a 
> cisco 3750 switch with Jumbo frames
> enabled)

Note that if these are Cisco routers, with the exception of the high-end kit
(i.e., 7600, XR 12000, CRS-1), Cisco don't generally support baby giant or
jumbo frames on their FE cards (although we are now seeing support for being
able to change the MTU on FE interfaces on the 7200 for much more recent
code).

> When i change the Gigabit interface to a FastEthernet interface, the 
> MPLS comes up.

Could we see some of your configurations on both routers (I'm assuming these
are Cisco)? If possible, can you send?

* sh run int <interface>
* sh int <interface>
* sh mpls interfaces
* sh mpls ldp neighbor

It'd be good to also look at your IGP configuration.

Recommend that you also have these commands by default in your global
configuration:

* mpls label protocol ldp
* mpls ldp router-id Loopback0

> I would like to know if it's possible to bring up MPLS up between two 
> disimilar interfaces.

It is possible - I've done it before.

Cheers,

Mark.