On 16 December 2016 at 14:01, CiscoNSP List <[email protected]> wrote: > Hey Adam - Have a TAC case open atm on ASR920 rLFA FRR (Tunnels being > created, when they shouldnt, and not used)...anyway, from this case, MPLS, > OSPF + ASR920 Dev teams have been working on it, and they have stated that > "ISPF conf under router ospf is not recommended anymore. The command will > soon be deprecated." - Its not related to the tac case, its was just a > recommendation from them....I asked why is it being deprecated, and the > reason they gave is that was introduced to improve convergence on slower > processors, processors are fast now, so it is no longer needed.....somewhat > strange, but I pressed them for more info, and that is all that they have > provided so far... >
In the case of IP FRR (r)LFA, iSPF is not a recommended setting under OSPF. When there is a failure with FRR LFA enabled, my understanding is that traffic will re-route via the backup LSP however the entire OSPF DB needs to be crawled as a new backup tunnel(s) needs to be calculated now, iSPF could hinder this process because not all possible paths would be explored in the OSPF DB, instead the first "suitable" match would be used. That is what Cisco had lead me to believe although it was unclear at the time so happy to be corrected here. There is a note on the Cisco doc's that says something like "The OSPF/ISIS configuration option "ispf" is not recommended although it is supported" with no further explenation so that we may decide whats best for us :s Cheers, James. _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
