The Priority Queue dives deep today, with a discussion of using EVPN as an enterprise data center interconnect. This is not a feel-good, fluffy podcast about how nice EVPN is and the fun things we someday hope to be able to do with it. Rather, this show gets right into the weeds on EVPN with the specific use-case of DCI.
Join Ethan Banks as he interviews double JNCIE Clay Haynes on setting up BGP adjacencies, creating EVPN address families, interpreting BGP output containing EVPN NLRIs, handling VTEPs, walking a packet through end to end, and useful commands to know.
More about EVPN?
- Show 196 – EVPN Introduction & Use-Cases With Russ White + Jeff Tantsura
- Show 233 – Cisco Nexus Using BGP As A VXLAN Control Plane – Sponsored
- EVPN: Intro To Next Gen L2VPN
- MPLS in the SDN Era
- Rick Mur’s Blog – EVPN (RFC7432) Explained and EVPN Configuration
- Dan Houtz – Configuring EVPN on Juniper QFX
Want to follow Clay?
Section 1 – What is EVPN?
- VPN – not IPSEC, but a virtual private network nonetheless.
- Provides L2 or integrated L2+L3 VPN.
- Implemented in the control plane using multiprotocol BGP.
- Implemented in the data plane with your choice of…
- Overlay such as VXLAN
- Provider Backbone Bridging (PBB)
Section 2 – What is EVPN good for in the real world?
- In a nutshell, it carries entire Ethernet frames across an L3 infrastructure.
- When using MP-BGP as a control plane, MAC addresses are advertised between BGP peers.
- A major use case for this is DCI.
- Stretching L2 between data centers is a design problem that needs special handling to implement safely.
- Extending failure domain of STP.
- Sub-optimal FHRP = traffic trombone.
- EVPN handles some of these stretched L2 issues.
- What vendors support EVPN on what platforms?
Section 3 – Let’s implement EVPN as an enterprise DCI.
- First, some terms.
- Ethernet segment
- Ethernet tag
- Ethernet segment identifier
- EVPN Instance (EVI)
- Then, some components
- EVPN overlay format of NVO.
- VXLAN tunnels & VTEPs
- MP-BGP peers sharing EVPN data
- Packet walk time! I’ve got these two endpoints on the same stretched L2 segment that need to talk to each other, separated by L3 infrastructure…
- Lessons learned.
- Architecture traps to avoid.
- Redundancy concerns.
- Troubleshooting tips.
- Reading the BGP table.
- Useful commands to know.