VXLAN Part XI: Using vPC Peer Link as an Underlay Backup Path

Edited: Wednesday, 5 September 2018 | Toni Pasanen

This short post shows how VTEP Leaf switch can use a vPC peer link as a backup path to Spine switch in a situation where the Leaf switch loses connection to the Spine switch. This is recommended redundancy model when using vPC in VXLAN BGP EVPN fabric. Just like in my previous posts, I am using only one Spine switch to keep things as simple as possible.

Figure 11-1: Example Topology and IP addressing

VXLAN Part X: Recovery issue when BGP EVPN peering uses the same loopback interface as a source than VXLAN NVE1 interface

Now you can also download my VXLAN book from the Leanpub.com 

"Virtual Extensible LAN VXLAN - A Practical guide to VXLAN Solution Part 1. (373 pages)

Does it really matter if the NVE1 interface of a VTEP switch and BGP EVPN use the same Loopback interface IP address as a source or should there be a dedicated Loopback interface for BGP EVPN? In this post, I am trying to give an answer by showing the difference in BGP EVPN convergence process for both of these design options.

  Figure 10-1: VXLAN BGP EVPN Example Topology and IP addressing

VXLAN Part IX: VXLAN BGP EVPN - vPC

This post describes how the Multi-Chassis Link Aggregation Group (MC-LAG) technology using virtual PortChannel (vPC) works in a VXLAN BGP EVPN fabric. I will first go through the vPC configuration with a short explanation and then I’ll show the Control- and Data Plane operation from VXLAN BGP EVPN perspective by using various show commands and packet capture. I am also going to explain the “Advertising VIP/PIP” options using the external connection. Example topology is shown in Figure 9-1. Complete configurations of vPC peer switches Leaf-102 and Leaf-103 (Leaf-101 and Spine-11 configuration are the same than in the previous post) can be found from the Appendix 1 at the end of the post.

Figure 9-1: VXLAN BGP EVPN vPC Example Topology and IP addressing