In my previous post, we saw the theory behind hub-and-spoke VPN. We saw how H/S involves multiple VRFs with cross-importation between them, and we traced the basic flow of a route advertised from one spoke to another. Next, we are going to look at two options for configuring H/S VPNs. In this post, I will […]
Category: Junos
Hub and Spoke VPN Part 1
One of the JNCIE-SP exam objectives I found difficult was hub and spoke VPN. Conceptually it’s not easy, and as is often the case, the documentation is only somewhat helpful. This series of posts is designed to walk you through the concepts of hub and spoke VPN, as well as its basic configuration using BGP, […]
RIB Group Confusion
This article continues to be the most popular one on this blog. However, I published it back in 2014 while I was working on my JNCIE-SP, and that was a long time ago. I now work at Cisco and do not have access to Junos, and my memory of Junos is getting spotty. I am […]
Juniper’s mysterious inet.3 table
When I first started configuring MPLS on Juniper routers, I came across the strange and mysterious inet.3 table. What could it possibly be? When I worked in Cisco TAC I handled hundreds of MPLS VPN cases, but I never had encountered anything quite like inet.3 in IOS land. As I researched inet.3 I found the […]
IS-IS Levels and Adjacencies
In this post, we’ll be looking at IS-IS inter-area concepts, and hopefully clearing up some of the confusion ISIS areas create in the minds of engineers who are used to OSPF. ISIS handles areas quite differently from OSPF, and if you think about ISIS areas in OSPF terms you are likely to be confused by […]