Genie's Tech Blog

Where knowledge has no dimensions

Multicast Equal Cost Multipath (ECMP)

Hello Friends,  Its been a long while that I posted something interesting on my blog. Here comes something that might interest you. Today I am going to discuss on Multicast ECMP feature. But before we discuss this feature, lets first define the problem that we are trying to solve so that we know why we need this feature. Problem Definition: Currently if there are multiple equal-cost paths towards a PIM source or RP, only one of them will be selected as the RPF path. PIM will send joins o... [More]

Loop Free Alternate Fast-Reroute - IP LFA FRR

Hello Friends,  I am back with yet another discussion on a very interesting topic - IP LFA FRR. But before we discuss about this, lets first discuss the what was the need for such development. Problem: A change in network topology upon a failure triggers network wide convergence. For example, when a local link fails, a router currently must signal the event to its neighbors via the IGP, re-compute new primary next-hops for all affected prefixes, and then install those new primary next-ho... [More]

Reversible NAT

Hello Friends, Today I am going to discuss regarding reversible NAT.  Reversible NAT can be used in two situations 1) In dynamic NAT with route-map option and a NAT pool is being used R3(config)#ip nat inside source route-map MAP pool POOL ? mapping-id Associate a mapping id to this mapping overload Overload an address translation reversible Allow out->in traffic vrf Specify vrf When used in dynamic NAT, the reversible option is only usable after some is generated from insid... [More]