I got several questions along the lines of “why is Cisco pushing LISP instead of using EVPN in VXLAN-based Enterprise campus solutions?”
Honestly, I’m wondering that myself (and maybe I’ll get the answer in a few days @ NFD16). However, let’s start at the very beginning…
Last week Stephen Foskett and Greg Ferro brought back their merry crew of geeks (and a network security princess) for the third Networking Tech Field Day. We’ve met some exciting new vendors (Infineta and Spirent) and a few long-time friends (Arista, Cisco, NEC and Solarwinds).
Infineta gave us a fantastic deep-dive into deduplication math, and Spirent blew our socks off with their testing gear. As for the generic state of the networking industry, the “I’m excited” rating from last autumn changed to this (HT @reillyusa):
It’s hard for me to admit, but there just might be a corner use case for split subnets and inter-DC bridging: even if you move a cold VM between data centers in a controlled disaster avoidance process (moving live VMs rarely makes sense), you might not be able to change its IP address due to hard-coded IP addresses, be it in application code or configuration files.
Disaster recovery is a different beast: if you’ve lost the primary DC, it doesn’t hurt if you instantiate the same subnet in the backup DC.
Immediately after VXLAN was announced @ VMworld, the twittersphere erupted in speculations and questions, many of them focusing on how VXLAN relates to OTV and LISP, and why we might need a new encapsulation method.
VXLAN, OTV and LISP are point solutions targeting different markets. VXLAN is an IaaS infrastructure solution, OTV is an enterprise L2 DCI solution and LISP is ... whatever you want it to be.
In early autumn of 2010, a “DRAFT on Cisco Nexus 1000V LISP Configuration Guide” appeared on CCO. It’s gone now (and unfortunately I haven’t saved a copy), but the possibilities made me really excited – with LISP in Nexus 1000V, we could do close-to-perfect vMotion over any IP infrastructure (including inter-DC vMotion that requires stretched VLANs and L2 DCI today). Here’s what I had to say on this topic during my Data Center Interconnect webinar (buy a recording).
I’ve been mentioning LISP several times during the last months. It seems to be the only viable solution to the global IP routing table explosion. All other proposals require modifying layers above IP and while that’s where the problem should have been solved, expecting those layers to change any time soon is like waiting for Godot.
If you’re interested in LISP, start with the introduction to LISP I wrote for Search Telecom, continue with the LISP tutorial from NANOG 45 and (for the grand finale) listen to three Google Talks from Dino (almost four hours).