My New SR-MPLS Course, and Krzysztof’s SRv6 Blogs
My new four-day instructor-led SR-MPLS course is now live! In addition, my colleague Krzysztof Szarkowicz has written many free blog posts on SRv6. Click this post to find out all about it.
Read more
routing
IS-IS and Unnumbered Ethernet Interfaces in Junos
There’s a trick you can use to massively reduce the number of IPv4 addresses you need in your network. With a little tweaking and a little bit of love, you don’t need to use addresses at all on point-to-point Ethernet links. Let me show you how.
Read more
Your “Multihop” BGP Session Probably Isn’t Multi-Hop
BGP study guides tell you that loopback-to-loopback EBGP session require a TTL of 2 or more. The trouble is, they rarely say why. This leads new students to come to some very incorrect assumptions about how the TTL field works in IP. In fact though, you can absolutely have a TTL of 1! In this post we clear up all the confusion – and we even look at how you can use a TTL of 255 to bring extra security to your network.
Read more
Route Distinguishers: The Secret To Load Balancing In Multihomed MPLS VPNs
There’s three types of route distinguisher – and one of them unlocks some seriously useful advantages. If you don’t know how to use route distinguishers for load balancing inside an MPLS VPN, then this post is for you. Junos config, but vendor-neutral theory. Give it a read!
Read more
A COMPLETE BEGINNER’S GUIDE TO SUBNETTING
If you’re a newcomer to networking, chances are you’re struggling to get your head around subnet masks. Well don’t worry: your goth uncle is here to explain how it all works. CCNA and JNCIA/JNCIS students, click here for some cool new knowledge!
Read more
CLEAN UP YOUR ROUTING TABLE! REMOVING POINT-TO-POINT SUBNETS FROM IS-IS, IN JUNOS
Some ISPs like to remove point-to-point prefixes from IS-IS. This keeps their routing tables small and easier to read. But how does it work? Doesn’t this break things? What are the trade-offs? This post shows you how to configure this solution, and the things you’ll want to consider if you deploy it. It’s super-cool, and you’ll definitely enjoy seeing the mechanics in action!
Read more
What is MPLS? A Beginners Explanation, For Network Engineers
I recently received an email from someone asking if I knew a good complete beginners guide to MPLS. Their mail inspired me, so I wrote one for them – and now, I’m sharing it with you! If you’ve always wanted to know what MPLS is, click here to fulfill your deepest dreams.
Read more
L2VPN: THE LABEL BASE AND OFFSET, EXPLAINED!
Pseudowires are easy on the surface – but dig a bit deeper, and there’s some interesting complexity. Click here to learn the details about BGP-signalled L2VPNs!
Read more
MAXIMISE YOUR JUNOS NETWORK WITH MPLS, PART 1: RSVP BANDWIDTH & PRIORITIES
RSVP lets us create LSPs that reserve bandwidth in advance. And that’s exactly what this three-part blog post series is all about! In this first post we’re going to learn how we combine bandwidth and priorities to get the most out of the bandwidth in our network. Click here for good times!
Read more
BFD ON JUNOS! BIDIRECTIONAL FORWARDING DETECTION – JUNIPER-CONFIG, MULTI-VENDOR EXPLANATION!
BFD is a protocol that gives all your other protocols sub-second failure detection times. Very useful! This blog post uses Junos config, but the explanation is multi-vendor. Give it a read!
Read more