ISIS Metric types. Experimenting with wide and narrow metrics.

Narrow Metric: We all know that by default the metric value for the ISIS route is 10 and it keeps on adding 10 on crossing every single link. For example, if the prefix has reached the router by crossing three links them the metric value associated with the prefix should be 40. See below example… Read More ISIS Metric types. Experimenting with wide and narrow metrics.

GNS3 LAB : LFA(Loop free alternate) and RLFA(Remote-LFA) on Cisco Routers.

Convergence time is a problem that humankind is trying to resolve since the day IGPs were discovered. Every vendor keeps on pushing less convergence time. With low “hold time” intervals we somehow manage to decrease the convergence time but this also has a limit, and the chances of raising bigger problems increase when we keep… Read More GNS3 LAB : LFA(Loop free alternate) and RLFA(Remote-LFA) on Cisco Routers.

ISIS Continued…

Some more details about ISIS: Packet types in ISIS : Hello Packets : Just like other IGPs ISIS also uses hello packets to form the adjacency and as a keepalive mechanism. ISIS has many hello packets intermediate system to intermediate system hello(IIHs), End system to intermediate system hellos(EIHs- sent to mac 09-00-2B-00-00-05), Intermediate system to… Read More ISIS Continued…