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.
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juniper
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.
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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.
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How to Increase the CLI Character Limit in Junos
Networking devices like Junos will cut off your CLI input if you type too much. But did you know there’s an easy fix? Let me show you.
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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!
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Junos: IS-IS Study Notes, Part 5 – Troubleshooting (For JNCIS-SP and JNCIS-ENT Students)
It’s the fifth and final part of our lessons on IS-IS! You’re now ready to learn how to troubleshoot and verify everything you’ve done so far. You’re really close to the finish line, so don’t give up!
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How To Read A Junos Class-Of-Service Configuration
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!
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Junos: IS-IS Study Notes, Part 4 – Levels, Areas, The Attached Bit, and Default Routes
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!
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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!
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SNMP OID: THOSE RANDOM NUMBERS ACTUALLY MEAN SOMETHING!
I bet you’ve looked at SNMP Objects like 1.3.6.1.2.1.2.2.1.7 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!
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