ASR9000 BVI not able to route further if used with VRF

[andresfcl]

HI,

I an running into a serious issue using BVI on ASR900, since the IOX XR does not support SVI i did have to create BVI, but the problem are that the BVI are used on my PE as WAN connectivity to the clients owned WAN ROUTERS, I am able to have connectivity from one PE (7600) that has configured and SVI to the other PE(ASR9006) that has configured and BVI but i not able to have further connectivity into the ASR side.

Let me explain me

My customer has a LAN on the main site called siteA  the LAN segment is 10.254.0.0/16 and it is behind a 7600 router that has and SVI acting as a WAN between the customer and the PE, the main site A has conectivity with other sutes called B, C and is working fine..., but we recently added ASR9006 as PE, and on one of those new PEs my client has a SiteF which connect to the PE trough the use of and SVI that belong to L2 bridge domain that, the SVI acts as WAN for my client EDGE router on the siteZ, teh problem is that i do have connectivity from the LAN on the main siteA all the way to THE SVI as well as the  WAN IP of my clients Edge router on remote SiteF, but i can not ping from LAN to LAN.

The SVI on the 7600 and the BVi At the 9006 belong the the same VRF

What is weird is that from the PE(ASR9006) i am able to ping the remote siteZ LAN as well as the LAN on the main SiteA, and vice-versa,

but from the LAN on the remote siteF I am able to ping only to the SVI on the ASR9006 but no further and also, From the main siteA i am able to get to the WAN of the remote siteZ which resides on the same segment of the BVI configured on the ASR9006 but i not able to ping to the LAN behind the SVI.

When i did configured the IP on the remote siteF directly on the physical interface there is no problem and i have full conectivity but when i do use the BVI i not able to route further than the BVI. to the remote siteF LAN.

The issue is that i not able to let the IP over the physical interface since it needs to be on BVI because the PEs are in scheme of double redundant PE that aggregate traffic form RINGS that are running REP therfore i do need of bridge domaind and BVI to provide redundancy.

[andresfcl]

Thanks the issue i have it was discused on other two cases under the support community,

Thnaks to Mattew  Ayre y

MAttew "The reason it doesn't work is because label switching on a VRF aware BVI is only supported in the per-vrf label allocation mode. There's a mention of this in the configuration guide shown here;

"VRFs for IPv4 (Per-VPN label VRFs only—not per prefix)"

http://www.cisco.com/en/US/docs/routers/asr9000/software/asr9k_r4.1/interfaces/configuration/guide/hc41irb.html#wp1030591

The change you should be able to observe is that if you create a second route, for example 192.168.200.66/32. It will be allocated the same label as the .65/32 prefix. When using per-prefix label allocation mode the label for each prefix would be unique.

You should be able to verify this with "show mpls forwarding vrf Ga" after adding an additonal route.

HTH,

Matt Ayre"

And tahnks to

Alexei Kiritchenko

  on Aug 20, 2012 6:10 AM

Hi Pichet,

Thx for opening the ticket and here is the summary of our troubleshooting session for the rest of the world

BVI does not support native MPLS forwarding and hence we need to use per-vrf allocation mode:
http://www.cisco.com/en/US/docs/routers/asr9000/software/asr9k_r4.1/interfaces/configuration/guide/hc41irb.html#wp1030591 

With this configuration we'd use an aggregate label and would do VRF IP lookup instead when a packet arrives from the core.

Regards,