23 Oct
2015
23 Oct
'15
3:35 p.m.
A lot of carriers use ISIS in the core so they can make use of the' overload bit' with a 'set-overload-bit on-startup wait-for-bgp". Keeps them from black holing Traffic while BGP reconverges., when you have millions of routes to converge it can take forever. It's also a really handy tool when you're troubleshooting or repairing a link, set the OL bit, and traffic gracefully moves, then when you're done it gracefully moves back. You can do the same thing with the Metric, and Cost in OSPF, just not quite as elegant.
That feature is also present in OSPF. 'max metric router-lsa'.