N9300/NV Overlay - Add switch,change from single switch to vpc

[jimmy0460]

We have 5 switches in production. 2 at HQ, 2 at PDC. 1 at DR. The 5 are eBGP peered and we have a VXLAN overlay between sites. Think multi pod but more than one DC. Anyways, I want to add a second switch at the DR site. I’ve never stood up a VPC after the bgp peering. My questions:

What is least intrusive process to add the second switch?

What do I need to plan for in terms of downtime?

What will happen to the routing when the VPC initially comes up?

[M02@rt37]

Hello @jimmy0460,

First, pre-config: configure the shiny new swich with basic settings, ensure it's running the good Firmware

Then, configure vPC (domain/peer-link and so on) between the existing and the new switch  -- check vPC consistency.

Configure BGP peering between the new switch and the existing swtiches at the DR and HQ sites. Ensure that BGP config; including route advertisement and neighbor statements, is consistent accros alls swtiches.

Configure VxLAN overlay on the new switch, VNI and other relevant parameters.

Validate the connectivity between the new switch and the others.

In terms of downtime, the least intrusive process would involve performing the configuration and verification steps without disrupting the existing network. This can be achieved by carefully planning and implementing changes during a maintenance window or low-traffic period. By following best practices and ensuring consistency in configuration, the impact on routing and connectivity can be minimized.

When the vPC initially comes up, the existing switches will recognize the new switch as a vPC peer and establish the vPC domain. The routing behavior should remain stable as long as the BGP peering and VXLAN configuration are consistent across the switches.