EVPN/MPLS Bridging Forwarding Model

Most networking engineers immediately think about VXLAN and data center switches when they hear about EVPN. While that’s the most hyped use case, EVPN standardization started in 2012 as a layer-2 VPN solution on top of MPLS transport trying to merge the best of VPLS and MPLS/VPN worlds.

If you want to understand how any technology works, and what its quirks are, you have to know how it was designed to be used. In this blog post we’ll start that journey exploring the basics of EVPN used in a simple MLPS network with three PE-routers:

Repost: What’s Wrong with Network Automation

Responding to my Infrastructure as Code Sounds Scary blog post, Deepak Arora posted an interesting (and unfortunately way too accurate) list of challenges you might encounter when trying to introduce network automation in an enterprise environment.

He graciously allowed me to repost his thoughts on my blog.

Why don’t we agree on that :

Repost: What’s Wrong with Network Automation

Responding to my Infrastructure as Code Sounds Scary blog post, Deepak Arora posted an interesting (and unfortunately way too accurate) list of challenges you might encounter when trying to introduce network automation in an enterprise environment.

He graciously allowed me to repost his thoughts on my blog.

Why don’t we agree on that :

netlab EVPN/VXLAN Bridging Example

netlab release 1.3 introduced support for VXLAN transport with static ingress replication and EVPN control plane. Last week we replaced a VLAN trunk with VXLAN transport, now we’ll replace static ingress replication with EVPN control plane.

netlab EVPN/VXLAN Bridging Example

netlab release 1.3 introduced support for VXLAN transport with static ingress replication and EVPN control plane. Last week we replaced a VLAN trunk with VXLAN transport, now we’ll replace static ingress replication with EVPN control plane.

Worth Reading: QUIC Is Not a TCP Replacement

Bruce Davie makes an excellent point in his QUIC Is Not a TCP Replacement article – QUIC not a next-generation TCP, it’s a reliable RPC transport protocol.

What Bruce forgot to mention is that we had a production-grade RPC transport protocol for years – SCTP (Stream Control Transmission Protocol) – but it had two shortcomings:

• It wasn’t invented by the right people;
• It used a different IP protocol number and thus upset every ossified middlebox in the Internet. QUIC hides on top of UDP (because adding extra headers makes at least as much sense as junk DNA).

Worth Reading: QUIC Is Not a TCP Replacement

Bruce Davie makes an excellent point in his QUIC Is Not a TCP Replacement article – QUIC not a next-generation TCP, it’s a reliable RPC transport protocol.

What Bruce forgot to mention is that we had a production-grade RPC transport protocol for years – SCTP (Stream Control Transmission Protocol) – but it had two shortcomings:

• It wasn’t invented by the right people;
• It used a different IP protocol number and thus upset every ossified middlebox in the Internet. QUIC hides on top of UDP (because adding extra headers makes at least as much sense as junk DNA).

Worth Reading: EVPN/VXLAN with FRR on Linux Hosts

Jeroen Van Bemmel created another interesting netlab topology: EVPN/VXLAN between SR Linux fabric and FRR on Linux hosts based on his work implementing VRFs, VXLAN, and EVPN on FRR in netlab release 1.3.1.

Bonus point: he also described how to do multi-vendor interoperability testing with netlab.

If only he wouldn’t be publishing his articles on a platform that’s almost as user-data-craving as Google.

Worth Reading: EVPN/VXLAN with FRR on Linux Hosts

Jeroen Van Bemmel created another interesting netlab topology: EVPN/VXLAN between SR Linux fabric and FRR on Linux hosts based on his work implementing VRFs, VXLAN, and EVPN on FRR in netlab release 1.3.1.

Bonus point: he also described how to do multi-vendor interoperability testing with netlab.

If only he wouldn’t be publishing his articles on a platform that’s almost as user-data-craving as Google.

Video: Kubernetes Services Types

Kubernetes services are like networking standards: there are so many to choose from. In his brief introduction to Kubernetes service types, Stuart Charlton listed six of them, and I’m positive there are more. That’s what you get when you’re trying to reinvent every network load balancing method known to mankind ;)

Video: Kubernetes Services Types

Kubernetes services are like networking standards: there are so many to choose from. In his brief introduction to Kubernetes service types, Stuart Charlton listed six of them, and I’m positive there are more. That’s what you get when you’re trying to reinvent every network load balancing method known to mankind ;)

Cumulus Linux Network Command Line Utility (NCLU)

While ranting about Linux data plane configuration, I mentioned an interesting solution: Cumulus Linux Network Command Line Utility (NCLU), an attempt to make Linux networking more palatable to more traditional networking engineers.

NCLU is a simple wrapper around ifupdown2 and frr packages. You can execute net add and net del commands to set or remove configuration parameters¹, and NCLU translates those commands into changes to corresponding configuration files.

Cumulus Linux Network Command Line Utility (NCLU)

While ranting about Linux data plane configuration, I mentioned an interesting solution: Cumulus Linux Network Command Line Utility (NCLU), an attempt to make Linux networking more palatable to more traditional networking engineers.

NCLU is a simple wrapper around ifupdown2 and frr packages. You can execute net add and net del commands to set or remove configuration parameters¹, and NCLU translates those commands into changes to corresponding configuration files.

Combining MLAG Clusters with VXLAN Fabric

In the previous MLAG Deep Dive blog posts we discussed the innards of a standalone MLAG cluster. Now let’s see what happens when we connect such a cluster to a VXLAN fabric – we’ll use our standard MLAG topology and add a VXLAN transport underlay to it with another switch connected to the other end of the underlay network.

Combining MLAG Clusters with VXLAN Fabric

In the previous MLAG Deep Dive blog posts we discussed the innards of a standalone MLAG cluster. Now let’s see what happens when we connect such a cluster to a VXLAN fabric – we’ll use our standard MLAG topology and add a VXLAN transport underlay to it with another switch connected to the other end of the underlay network.

Repost: On the Viability of EVPN

Jordi left an interesting comment to my EVPN/VXLAN or Bridged Data Center Fabrics blog post discussing the viability of using VXLAN and EVPN in times when the equipment lead times can exceed 12 months. Here it is:

Interesting article Ivan. Another major problem I see for EPVN, is the incompatibility between vendors, even though it is an open standard. With today’s crazy switch delivery times, we want a multi-vendor solution like BGP or LACP, but EVPN (due to vendors) isn’t ready for a multi-vendor production network fabric.

Repost: On the Viability of EVPN

Jordi left an interesting comment to my EVPN/VXLAN or Bridged Data Center Fabrics blog post discussing the viability of using VXLAN and EVPN in times when the equipment lead times can exceed 12 months. Here it is:

Interesting article Ivan. Another major problem I see for EPVN, is the incompatibility between vendors, even though it is an open standard. With today’s crazy switch delivery times, we want a multi-vendor solution like BGP or LACP, but EVPN (due to vendors) isn’t ready for a multi-vendor production network fabric.

netlab VXLAN Bridging Example

netlab release 1.3 introduced support for VXLAN transport with static ingress replication. Time to check how easy it is to replace a VLAN trunk with VXLAN transport. We’ll use the lab topology from the VLAN trunking example, replace the VLAN trunk between S1 and S2 with an IP underlay network, and transport Ethernet frames across that network with VXLAN.

netlab VXLAN Bridging Example

netlab release 1.3 introduced support for VXLAN transport with static ingress replication. Time to check how easy it is to replace a VLAN trunk with VXLAN transport. We’ll use the lab topology from the VLAN trunking example, replace the VLAN trunk between S1 and S2 with an IP underlay network, and transport Ethernet frames across that network with VXLAN.

Worth Reading: The Hierarchy Is Bullshit

Charity Majors published another masterpiece: The Hierarchy Is Bullshit (And Bad For Business).

I doubt that anyone who would need this particular bit of advice would read or follow it, but (as they say) hope springs eternal.