EVPN ESI Multihoming - Part I: EVPN Ethernet Segment (ES)

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)

This chapter introduces the standard based EVPN ESI Multi-homing solution in BGP EVPN VXLAN Fabric. It starts by explaining the mechanism of how CE device (Access switch or host) can be attached to two or more independent PE devices (Leaf switches) by using Port-Channel. This section discusses the concept of Ethernet Segment and Port-Channel. Next, this chapter explains how the BGP EVPN Route-Type 4 (Ethernet Segment Route) is for creating the redundancy group between the switches that share the ES. This section introduces the BGP EVPN Route-Type 4 NLRI address format. In addition, this chapter shows how switches belonging to the same redundancy group selects the Designated Forwarder (DF) for BUM traffic among themselves. Also, this chapter introduces the VLAN Consistency Check by using Cisco Fabric Service over IP (CFSoIP). The last two sections explain the Layer 2 Gateway Spanning-Tree (L2G-STP) mechanism and Core-Link Tracking system.

Part II introduces the BGP EVPN Route-Type 1 (Ethernet Auto-Discovery) and how it is used for convergence. Part III discusses the data flows between the hosts in normal and failure situation. Part II and III will be published later.

Figure 1-1: The VXLAN EVPN Multi-homing topology and addressing scheme.

VXLAN Underlay Routing - Part V: Multi-AS eBGP

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)

eBGP as an Underlay Network Routing Protocol: Multi-AS eBGP

This post introduces the Multi-AS eBGP solution in VXLAN Fabric. In this solution, a single AS number is assigned to all spine switches while each leaf switches (or pair of leaf switches) have unique BGP AS number. This solution neither requires “allowas-in” command in leaf switches nor “disable-peer-check” command in the spine switches, which are required in Two-AS solution. The “retain-route-target all” command and BGP L2VPN EVPN address family peer-specific route-map with an option “set ip next-hop-unchanged” is needed on the spine switch. This post also explains the requirements and processes for L2 EVPN VNI specific route import policy when automated derivation of Route-Targets is used. The same IP/MAC address scheme is used in this chapter than what was used in the previous post “VXLAN Underlay Routing - Part IV: Two-AS eBGP” but the Leaf-102 now belongs to BGP AS 65001.

Figure 1-1: The MAC/IP addressing scheme and eBGP peering model.

VXLAN Underlay Routing - Part IV: Two-AS eBGP

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)

eBGP as an Underlay Network Routing Protocol: Two-AS eBGP

This post explains the Two-AS eBGP solution in VXLAN Fabric, where there is single AS Area for all Leaf switches and other AS Area for all Spine switches. It also discusses how the default operating model used in eBGP peering has to be modified in order to achieve a routing solution required by VXLAN Fabric. These modifications are mainly related to BGP loop prevention model and BGP next-hop path-attribute processing.

Figure 1-1 illustrates the topology used in this chapter. Leaf-101 and Leaf-102 both belong to BGP AS 65000, while Spine-11 belongs to BGP AS 65099. Loopback interfaces used for Overlay Network BGP peering (L100) and for NVE peering (L50) are advertised over BGP AFI IPv4 peering (Underlay Network Control Plane). Host MAC/IP address information is advertised over BGP AFI L2VPN EVPN peering (Overlay Network Control Plane). Ethernet frames between host Café and Abba are encapsulated with a VXLAN tunnel header where the source and destination IP addresses used in the outer IP header are taken from NVE1 interfaces.

Figure 1-1: High-Level operation of VXLAN Fabric