Vxlan underlay backup routing SVI VLAN cross VPC Peer link interface！

[fly]

 becase we config peer-gateway and peer-switch feature under vpc .

I config vxlan underlay backup routing between two VPC leafs across peer-link

config like below url said at bottom

one question:

backup routing interface vlan just exist on peer-link , but when we config peer-switch on both leafs.

we found this vlan is putted into spanning tree backup state, and interfave vlan can't get up

 and ospf can't established,

so i change this vlan spanning tree priority on one leaf switch , and spanning tree state on this vlan ( peer-link interface） change to forwarding。 

is there other solution to resolve this problem?

 thank you!

Jere

https://www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus9000/sw/7-x/vxlan/configuration/guide/b_Cisco_Nexus_9000_Series_NX-OS_VXLAN_Configuration_Guide_7x/b_Cisco_Nexus_9000_Series_NX-OS_VXLAN_Configuration_Guide_7x_chapter_011.html

Enabling vpc peer-gateway configuration is mandatory. For peer-gateway functionality, at least one backup routing SVI is required to be enabled across peer-link and also configured with PIM. This provides a backup routing path in the case when VTEP loses complete connectivity to the spine. Remote peer reachability is re-routed over peer-link in his case. In BUD node topologies, the backup SVI needs to be added as a static OIF for each underlay multicast group.

[Rurick Kellermann]

Hi,

Did you configure the Vlan on both VPC Peers? 

May I ask, what is the version of NxOS running when you attempted to implement it?

[melchib]

Did you also remember to configure system nve infra-vlans <vlan-id> force for the vlan you are using for the backup routing SVI?

[Team Activation Center]

Hi ,

I'm trying today on 93180YC-FX3 with 9.3.8 release, the configuration as follow:

interface Vlan1
  description L3 Peer-Link
  no shutdown
  mtu 9216
  medium p2p
  no bfd echo
  no ip redirects
  ip address 100.100.133.254/31
  no ipv6 redirects
  ip ospf cost 1
  ip ospf network point-to-point
  ip router ospf UNDERLAY area 0.0.0.0
  ip ospf bfd
  ip pim sparse-mode

for now everythings work correctly (I've tested a failover) , in next days I'll do other test to discover something strange.

P.S. I've choosed VLAN 1 because it can't be configured in VXLAN neither per mistake, maybe the command system nve infra-vlans <vlan-id> do the same thing on another VLAN?