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New Member

Partial routing updates with MPLS via BGP

I am having an issue with only receiving a partial routing table at a new site connected via Verizon's MPLS service.

The routing protocol used for PE-CE is BGP. The routers involved are all 2821 running the same version of software - v12.4(11).

The new site receive route information for most of the existing sites, but does not get route info for a few specific sites. The BGP routing configuration is the same at all site except for the site specific information.

Basically, Site D is a new site. Site D receives routing info. for sites B and C, but not A.

Sites A receives route info for sites B and C, but not D.

A trace route from A to D, dies after the PE device at site D. A trace route from D to A fails imediately.

A sample of the BGP routing config is below:

router bgp 1

no synchronization

bgp log-neighbor-changes

redistribute eigrp ### metric 20

neighbor x.x.x.x remote-as #####

no auto-summary

I'm not sure if the issue is with our routing, or if Verizon's PE is not passing all the routing updates.

Anyone has any sugestions?

7 REPLIES
Super Bronze

Re: Partial routing updates with MPLS via BGP

For the new site D, use the show bgp neighbor command to see the routes being received from the provider peer and to confirm what site D is sending to the provider (you didn't mention whether sites B and C see D).

New Member

Re: Partial routing updates with MPLS via BGP

Sites B and C are receive route info for both Site A and D.

Sh BGP on A show no information for site D, and Sh BGP on site D show no information for A.

Both A and D show BGP entries for sites B and C.

Super Bronze

Re: Partial routing updates with MPLS via BGP

Assuming there's no inbound BGP filters, route maps, etc. on either site A and D, then if you haven't already, you could try a bgp clear inbound at both sites A and D. If routes still not there, might be time to contact MPLS vendor.

New Member

Re: Partial routing updates with MPLS via BGP

Unfortunately, the bgp clear did not work. so I'll be calling the vendor.

thanks for the hrlp.

Super Bronze

Re: Partial routing updates with MPLS via BGP

If possible, let us know about problem resolution.

Re: Partial routing updates with MPLS via BGP

Hi,

1st, if you are running bgp as a CE-PE routing protocol, the above shouldnt be the config sample. why are you redistributing Eigrp?

Could you check you BGP routing table at Site-A & D.

The Symptoms appears as there is no route back from Site-D to A.

This could be due to a lot of problems at the service provider, whether the Networks at Site-D are not advertised through MP-BGP or it could be a route-target issue at the service provider.

Pls let us know how you routing table look like at both sites.

HTH

Mohamed

Re: Partial routing updates with MPLS via BGP

Can you try configuring the following under the BGP session at D

router bgp 1

neighbor x.x.x.x allow-as in

Narayan

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