In certain situations an engineer may need to manipulate EIGRP metrics, and one method is to use Offset Lists to increase both the AD (Advertised Distance) and FD (Feasible Distance) of a route by a certain value – the offset. Offset List configurations define the following: route(s) that we want to amend the metric for […]
There are a couple of gotcha’s when running EIGRP over a WAN technology such as Frame Relay, as opposed to a LAN technology like Ethernet. To demonstrate one of them let’s consider a typical Frame Relay network operating in a hub and spoke configuration, with our HQ router being the hub and our East and […]
We know that enabling EIGRP on an interface has two effects: EIGRP Hello packets will start being sent out of the interface to multicast address 224.0.0.10. This means that neighbour relationships (adjacencies) can be formed with other routers directly connected to the same subnet and using the same EIGRP AS number the network that the […]
EIGRP will load balance traffic across up to 16 links (4 by default) of equal cost. One nice feature of EIGRP is that it can also be configured to load balance across unequal cost links, as opposed to other routing protocols like RIP and OSPF. Our topology is made up of two routers connected to each […]
In my previous post I covered authentication to improve the security of EIGRP routing. Next up we are going to look at route summarization. One feature of EIGRP is that you can summarize pretty much wherever you like, whereas with OSPF for example you are limited to summarizing at area boundaries. To re-cap, summarization is the […]
So, my CCNP studies slipped onto the back burner recently as I focussed on passing my JNCIA-Junos cert, so it’s time to pick up where my last post left off and move on from a basic EIGRP config to some more advanced stuff. We know that two EIGRP routers will become neighbours if they have the […]
I passed the JNCIA-JUNOS (JN0-101) exam today 🙂 after a couple of weeks study, so thought I’d knock up a quick blog post about the experience and how it compares to other vendor exams I’ve taken. Firstly, the main reason I went after this cert is that I worked on the deployment of a new […]
I’m currently working on an Avaya VOIP implementation, and thought I’d blog about some of the configuration steps involved along the way. First of all let’s set the scene with a massively oversimplified network diagram that shows how things hook together. We have a DHCP server and an Avaya CS1000E Communications Server, a Cisco […]
Well, that’s my first year of blogging done and dusted, so what did I achieve in 2012 and what would I like to do in 2013? 2012 was a really enjoyable year, and at the same time it was probably the most challenging of my career in Networking so far. I started the year intending to […]
Hello, is there anybody in there? Just nod if you can hear my EIGRP hello packets being multicast to 224.0.0.10…. Apologies to any Pink Floyd fans out there, but the opening line to Comfortably Numb describes perfectly what happens when an interface starts participating in an EIGRP routing process (well, not really). As […]