I’ve been in a lot of interesting discussions the last couple of days on what protocol to use for the underlay when building a VXLAN datacenter network. Do you use an IGP such as OSPF or ISIS or do you
Choosing the Underlay Protocol in a VXLAN Network
When building a VXLAN network, what are the considerations for choosing the underlay protocol such as OSPF, IS-IS, or BGP? You obviously want the design to be supported by your vendor of choice. Your staff should also be able to
Unnumbered Links In OSPF
This post is going to be a real deep dive! First, I want to send my sincere thanks to the maestro Peter Palúch and the guru Ivan Pepelnjak for helping me research this topic. Ivan wrote a couple of great
Building a VXLAN Lab Using Nexus9000v
As I dive into the world of VXLAN, I will need a lab as that is the best way to deepen the learning process and to get hands-on experience with a protocol. I will be building a Cisco Nexus9000v lab
Introduction to VXLAN
In the previous post, we looked at some of the challenges with L2-based networks. Now let’s start diving into what VXLAN is and what it can provide. First, let’s talk about overlays. Overlays Overlays are not new. We have had
OSPF Convergence In a Hub and Spoke Topology
My dear friend Micheline Murphy posted an excellent question on OSPF in a Hub and Spoke topology at the Cisco Learning Network. The scenario is a Hub and Spoke topology with two Hub routers that are ABRs belonging to area
OSPF Design Considerations
Introduction Open Shortest Path First (OSPF) is a link state protocol that has been around for a long time. It is geneally well understood, but design considerations often focus on the maximum number of routers in an area. What other
OSPF – Non Broadcast and Point to Multipoint
Introduction There was a discussion on a forum about the point to multipoint network type in OSPF. What is the purpose of it and why are /32 endpoints advertised? To understand the solution we must first understand the problem. This
Some pointers on OSPF as PE to CE protocol
There was a discussion at the Cisco Learning Network (CLN) about OSPF as PE to CE protocol. I wanted to provide some pointers on using OSPF as PE to CE protocol. RFC 4577 describes how to use OSPF as PE
Default routes in BGP
I have seen in forums and in other places that some find that the default route in BGP is a bit confusing. There are multiple ways of orginating a default route in BGP. To start this is the topology used: