On Fri, 18 Apr 2008, Plz wrote: > Here is the problem, in my opinion, when A & B redistribute this ospf > external route into ISIS, A&B should have this route > in both OSPF & ISIS,(A advertise this route to B via ISIS, and B advertise > this route to A in ISIS). > The fact is not this. > When i show route on A, i find 1 route in OSPF, and another in ISIS(B > advertise to A). But only the ospf route is found on B. > Seems that A didn't advertise this route 1.1.1.1/32 to B. This route ( > 1.1.1.1/32) was redistribute into ISIS on A coz i > find it in the A's ISIS database. Wat's more, A didn't advertise this route > to the uplink router either. > > Could anyone explain this? Any advise ll be appreciated.
The default OSPF preferences are better than IS-IS. IS-IS doesn't redistribute a route that isn't active. Also, if you receive an IS-IS route with (say) metric 10, and your IS-IS redistribution policy were to set your advertised metric to 15, no redistribution occurs because IS-IS already has a better route. If you had this problem with BGP advertisements, "advertise-inactive" would help you; in this case it doesn't. You should probably look at the metrics of IS-IS routes and possibly routing protocol preferences (e.g. make IS-IS preferred over OSPF). -- Pekka Savola "You each name yourselves king, yet the Netcore Oy kingdom bleeds." Systems. Networks. Security. -- George R.R. Martin: A Clash of Kings _______________________________________________ juniper-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/juniper-nsp
