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.
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!
Struggling to read Junos Class-of-Service config? This post is for you: it shows you where to start, what order to read each piece in, and what to look for. After this you’ll have no problem working out exactly what’s going on!
The fourth part in this intro to IS-IS series tackles areas, and how they’re different to levels. A lot of new students confuse them, and a lot of documentation gets it wrong too! This post clears everything up for you, and will make you super confident. You’ll also learn about IS-IS default routes, and route leaking from L2 to L1. Give it a click!
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!
I bet you’ve looked at SNMP Objects like 126.96.36.199.188.8.131.52.1.7 and wondered what on earth it means. Well, let me satisfy your curiosity: by the end of this post you’ll learn how to find SNMP objects to monitor anything you can think of, and you’ll even learn how to know what this number means by sight!
In this post we show how to configure RSVP in Junos – and then we roll up our sleeves to look at some packet captures of the PATH and RESV messages on the wire. There’s some mighty fine learning in this post!
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.