VXLAN EVPN Border Leaf Redistribution problem

[rwu]

Hi, DC experts
I'm running into a problem when doing a lab on VXLAN EVPN.

Based on the attached topology, two leafs (Leaf-1, Leaf-2) and one border leaf. The border leaf set up OSPF (under vrf Tenant-1) with top left external router. Symmetric routing is being used so L3VNI is being used.

Everything has been tested inside the VXLAN fabric. The only problem is on border leaf when redistributing BGP to OSPF. On the external router, it can't receive host route 1.1.1.10/32 and 2.2.2.11/32. The redistribution from OSPF to BGP on border leaf works fine because leaf-1 and leaf-2 can receive external route 10.10.10.10/32 L3VNI (loopback0 address of external router).

Could you please help check the attached configuration of Border leaf? I've done many checks but can't find out what is missing.
On border leaf, show ip ospf database external vrf Tenant-1, nothing was there. BGP EVPN /32 routes 1.1.1.10/32 and 2.2.2.11/32 should've been there.

Many thanks!

[Sergiu.Daniluk]

Hi @rwu 

Can you share the config for route-map bgp-to-ospf as well?

Cheers,

Sergiu

[rwu]

Hi, @Sergiu.Daniluk 

    It's in the attached config of Border leaf:

    route-map bgp-to-ospf permit 10

    There's actually nothing in it, so it permits all. I tried creating a prefix-list only with 1.1.1.10/32 in it and match this prefix in route-map bgp-to-ospf, but it didn't make a difference. On Border leaf, in show ip ospf database external vrf Tenant-1, there's still nothing in it, so the top left external router can't receive /32 routes. 

    Thanks :) 

[Sergiu.Daniluk]

Hello,

Ah yes. It's in the config. I think i mistyped something when I searched the cfg for it.

Can you share the "show bgp l2vpn evpn" output?

Also, I do not see the the L2 VNIs configured under the NVE. Did you removed that while sharing the config, or you only wanted to have the L3 VNI configured? Have you tried adding L2 VNIs?

Thanks,

Sergiu

[rwu]

Hi, 

    Here's the output:

Border-Leaf# show bgp l2vpn evpn
BGP routing table information for VRF default, address family L2VPN EVPN
BGP table version is 1070, Local Router ID is 44.44.44.44
Status: s-suppressed, x-deleted, S-stale, d-dampened, h-history, *-valid, >-best
Path type: i-internal, e-external, c-confed, l-local, a-aggregate, r-redist, I-i
njected
Origin codes: i - IGP, e - EGP, ? - incomplete, | - multipath, & - backup

Network Next Hop Metric LocPrf Weight Path
Route Distinguisher: 11.11.11.11:32770
*>i[2]:[0]:[0]:[48]:[aabb.cc00.c000]:[0]:[0.0.0.0]/216
222.222.222.222 100 0 i
*>i[2]:[0]:[0]:[48]:[aabb.cc00.c000]:[32]:[2.2.2.11]/272
222.222.222.222 100 0 i

Route Distinguisher: 22.22.22.22:32769
*>i[2]:[0]:[0]:[48]:[aabb.cc00.b000]:[0]:[0.0.0.0]/216
221.221.221.221 100 0 i
*>i[2]:[0]:[0]:[48]:[aabb.cc00.b000]:[32]:[1.1.1.10]/272
221.221.221.221 100 0 i

Route Distinguisher: 44.44.44.44:3 (L3VNI 50999)
*>i[2]:[0]:[0]:[48]:[aabb.cc00.b000]:[32]:[1.1.1.10]/272          --------> from leaf2
221.221.221.221 100 0 i
*>i[2]:[0]:[0]:[48]:[aabb.cc00.c000]:[32]:[2.2.2.11]/272           --------> from leaf1 
222.222.222.222 100 0 i
*>l[5]:[0]:[0]:[32]:[10.10.10.10]:[0.0.0.0]/224
223.223.223.223 41 100 32768 ?

    The above two L3VNI host routes should've been redistributed into OSPF under vrf Tenant-1. 

    For nve 1 configuration, I had both L2VNI in it and it didn't make any difference. Then I realized that it's border leaf with no hosts connected to it, so L3VNI is the only thing I need. So I removed L2VNI. 

=========================

    I think the only related commands are:

    (1) 

    router ospf 1
     router-id 44.44.44.44
     vrf Tenant-1
        redistribute direct route-map bgp-to-ospf               -------> can be removed actually
        redistribute bgp 65000 route-map bgp-to-ospf       -------> This is the one  related

    (2) Under BGP, advertise l2vpn evpn:

    router bgp 65000
(truncated here)
    vrf Tenant-1
        address-family ipv4 unicast
        advertise l2vpn evpn ----------------------->>>>>         kind of suspected this command doesn't work? 

    Thanks. 

[Sergiu.Daniluk]

Hello,

Yep, the L3 VNI should be sufficient for this purpose. And yes, the config looks ok.

What platform/version do you have as BL?

Thanks,

Sergiu

[rwu · Accepted solution]

Hi, Sergiu

The lab is based on vNexus9K.  NXOS: version 7.0(3)I7(7)  

Do you know what? It never occurred to me that the NXOS version might be related to that, but since you asked, I took a look at the release note and it said:

" When upgrading to Cisco NX-OS Release 7.0(3)I7(7) running EVPN VXLAN and redistributing BGP EVPN into OSPF, match the route-type internal under the relevant route-map configured."

After I added "match route-type internal" under route-map bgp-to-ospf, it worked as I expected!!! 

Many thanks for your time and help! 

[Sergiu.Daniluk]

Nice! Kudos for finding the missing command.

Cheers,

Sergiu