BGP over VPC

[blackmetal]

Hello,

here is my network topology : https://i.imgur.com/LYJtGGv.png

i have a customer which is connected to my top of rack switch and my top of rack switch has 2x 10g LACP towards my both Cisco Nexus 3k and both of my Nexus 3k has VPC PEER link, here is customer router interface vlan config :

interface vlan547

ip address 192.168.20.1/30

then my customer will set 192.168.20.2/30 in own router and now we want to establish bgp from customer router towards n3k, but if we do this then bgp flap occur, because sometimes bgp request send to first n3k and sometimes send to second n3k, what is the solution for this? also i know one of the solutions is to connect my customer router directly to both of my n3k then establish 2 different bgp or form LACP or such things, but i want to know if we can find any solution in this senario. Thank you.

[Reza Sharifi]

Hi,

See page 75 in this link. The customer router should peer directly with parent switches (n3ks in your case) and not the TOR equipment.

https://www.cisco.com/c/dam/en/us/td/docs/switches/datacenter/sw/design/vpc_design/vpc_best_practices_design_guide.pdf

HTH

[MHM Cisco World]

do this 
peer-gateway 
layer3 peer-router <- this will not decrement the TTL and make packet drop.
in both Nexus and check again.

[blackmetal]

when i enter vpc domain 1 configuration it has only "layer3 peer-router" and "layer3 peer-router syslog" do i enable layer3 peer-router?

and would you tell me exactly what does layer3 peer-router do ?

then i can send 192.168.20.2/30 in my customer router and then i can have bgp session  from 192.168.20.2 towards both nexus with 192.168.2.1 ip with no bgp flap?

[MHM Cisco World]