Default route propogation in BGP and VRF

[awickers]

Hi

I have just implemented VRF for a MPLS & Internet service on a shared 3845 platform and I have now lost my default route propagation to my remote sites.

Before implementing VRF the default route propagated fine to the remote routers and I had a route of last resort on all of them. After implementing VRF the default route was still on the 3845 but the route of last resort is no longer present on the remote routers.

It is definitely the VRF config causing the problem because as soon as I remove the vrf forwarding command from the subinterface the route of last resort appears on the remote routers, I have searched for a solution on the forum and Cisco web site without any luck. Although I think it may be something to do with routes leaking between the vrf and the global routing table.

VRF config is

ip vrf DIA

description *** DIA VRF Instance ***

rd 3549:2

route-target export 3549:2

route-target import 3549:2

interface GigabitEthernet0/1

description *** Internet Connection ***

ip vrf forwarding DIA

ip address 208.50.120.33 255.255.255.224

no keepalive

arp timeout 1500

interface Serial2/0.518 point-to-point

description ***** Internet Connection ****

ip vrf forwarding DIA

bandwidth 12000

ip address 207.138.94.182 255.255.255.252

frame-relay interface-dlci 518

Static route are

0.0.0.0 0.0.0.0 10.1.3.253 (internal interface of firewall)

ip route vrf DIA 0.0.0.0 0.0.0.0 207.138.94.181

ip route vrf DIA 208.50.120.32 255.255.255.224 207.138.94.181

BGP config is

router bgp 64610

no synchronization

bgp log-neighbor-changes

network 10.z.z.z mask 255.255.240.0

redistribute static

neighbor x.x.x.x remote-as 6745

neighbor x.x.x.x ebgp-multihop 4

neighbor x.x.x.x version 4

neighbor y.y.y.y remote-as 3549

eighbor y.y.y.y local-as 64875

neighbor y.y.y.y version 4

neighbor y.y.y.y prefix-list DIA-out out

no auto-summary

!

address-family ipv4 vrf DIA

neighbor y.y.y.y remote-as 3549

neighbor y.y.y.y local-as 64875

neighbor y.y.y.y version 4

neighbor y.y.y.y activate

neighbor y.y.y.y prefix-list DIA-out out

no synchronization

network 208.50.120.32 mask 255.255.255.224

exit-address-family

Hope someone can help.

Regards Andrew

[cisco_lad2004]

can u submit the below please ( with VRF applied to interfaces):

1-sh ip route 10.1.3.253

2-sh ip route vrf DIA 10.1.3.253

Sam

[awickers]

Sam results are as follows

Without VRF enabled

router#sh ip route 10.1.3.253

Routing entry for 10.1.0.0/20

Known via "connected", distance 0, metric 0 (connected, via interface)

Advertised by bgp 64610

Routing Descriptor Blocks:

* directly connected, via GigabitEthernet0/0

Route metric is 0, traffic share count is 1

routersh ip route vrf DIA 10.1.3.253

% Network not in table

With VRF enabled

sh ip route 10.1.3.253

Routing entry for 10.1.0.0/20

Known via "connected", distance 0, metric 0 (connected, via interface)

Advertised by bgp 64610

Routing Descriptor Blocks:

* directly connected, via GigabitEthernet0/0

Route metric is 0, traffic share count is 1

Router#sh ip route vrf DIA 10.1.3.253

% Network not in table

Andrew

[cisco_lad2004 · Accepted solution]

great !

you have a default route in global pointing at 10.1.3.253 which is connected to GE0/0.

under BGP (IPV4) u redistribute static to our remote sites.

Adding "default-information originate" should propagate a default route to remote sites, regardless of what happens under ur VRF config.

The VRF config as I understand is between u and remote AS for peering.

HTH

Sam

[awickers]

Sam

Adding the default-information originate to the BGP config worked, we now have the default route propagating out to the remote MPLS connected sites and internet access via gi0/1

Many thanks for all you help

Regards Andrew

[cisco_lad2004]

glad to hear !

I spotted this from start, but was not too sure about ur set up and what u aimed to achieve.

Sam