RIPv2 gets a bad rap, in my opinion, because it still has some suitable network topologies that it works well for. It’s kind-of like the visceral reaction some people have towards static routing. There’s no ‘right’ answer for most of these design types of decisions, only ‘better’ answers. As for RIPv2, let’s see some ofContinue reading “RIPv2 advantages & disadvantages”
Category Archives: fast convergence
Fast convergence & carrier-delay
I’m reading Definitive MPLS Network Designs and I came across an interesting detail with respect to carrier delay. Carrier delay is how long to wait before signaling to the control plane a detection of a network link failure. By default, the interface will wait 2 seconds before signaling failure. Typically, it is a best practiceContinue reading “Fast convergence & carrier-delay”
Fast Convergence Techniques: IS-IS
We would be irresponsible as network designers if we did not study and appreciate IS-IS for the problems it can solve. IS-IS is a link-state protocol similar to OSPF. IS-IS uses TLVs (similar to BGP), and is thus easily extended. IS-IS and OSPF are the two choices you have when deploying TE on MPLS networks,Continue reading “Fast Convergence Techniques: IS-IS”
Fast Hellos
One thing to think about from a design perspective is the scalability of fast hellos. If you have a router with several hundred interfaces, each sending subsecond hellos, the RP has to process a lot of hello packets. If you can design your network to have point-to-point interfaces, the interface flap will most likely beContinue reading “Fast Hellos”
Fast Convergence Techniques
In reading the SRND on router access layer there are a few key takeaways.On page 5 it says: “Cisco recommends a routed network core in all cases.” Let’s examine the reasoning behind this statement. First of all, what’s the alternative? You can have a layer-2 core where your devices simply switch frames at layer-2. ThinkContinue reading “Fast Convergence Techniques”
security without obscurity 