This has been there for a while, so if it was overlooked it has been ongoing. :)
We ran in to this when migrating from some M20s/M40e's to M320s. Had to remember to deactivate the interface on the old router as it was still showing the /32 side of the connected as active even when the fiber was pulled... -Jeff On Apr 22, 2010, at 12:09 PM, Paul Stewart wrote: > Hey Richard... > > That is an interesting find - my thought would have been the same. Don't > install the route OR the host route into the table unless it's active. > > Why would you have a route entry exist to an interface that is down and > could never pass traffic? Just my thoughts... > > Would be interesting to hear from JTAC if this was a design "feature" or an > overlooked "oops".... > > Paul > > > -----Original Message----- > From: juniper-nsp-boun...@puck.nether.net > [mailto:juniper-nsp-boun...@puck.nether.net] On Behalf Of Richard A > Steenbergen > Sent: April-22-10 3:03 PM > To: juniper-nsp@puck.nether.net > Subject: [j-nsp] /32 host routes on down interfaces > > So I just noticed an interesting behavior which I think is a bad thing, > but I want to see what other people think. > > If you take an interface and put an IP route on it, like say: > > interfaces { > xe-0/0/0 { > unit 0 { > family inet { > address 1.1.1.1/30; > } > } > } > } > > And the above interface is DOWN, the 1.1.1.0/30 route is not installed > to the routing table like one would expect, but the 1.1.1.1/32 HOST > ROUTE is: > > inet.0: 326321 destinations, 3502101 routes (319320 active, 11 holddown, > 316892 hidden) > Restart Complete > + = Active Route, - = Last Active, * = Both > > 1.1.1.1/32 *[Local/0] 00:00:05 > Reject > > And if you try to route traffic through the box for 1.1.1.1, it is > rejected. The same is true even if you admin down the interface with > "interface xe-0/0/0 disable", it always installs the /32 local route. > > This seems like a bad thing to me. If the interface is down (either link > or admin) I don't see why you'd need the local route installed in the > routing table? > > I'm assuming the reason nobody has complained before is it doesn't break > that much stuff, since the only time most people talk to an interface > host route is via the directly conected interface. The only reason I > noticed it at all was we were doing router migrations and pre-staging > the config on new router ports, so the IP existed on multiple routers > but only 1 link would be active at any given moment. And yes I know you > can always work around this by deactivating the interface so the IP > config doesn't go into the parser at all, I'm just wondering why it > would be designed this way in the first place. :) > > -- > Richard A Steenbergen <r...@e-gerbil.net> http://www.e-gerbil.net/ras > GPG Key ID: 0xF8B12CBC (7535 7F59 8204 ED1F CC1C 53AF 4C41 5ECA F8B1 2CBC) > _______________________________________________ > juniper-nsp mailing list juniper-nsp@puck.nether.net > https://puck.nether.net/mailman/listinfo/juniper-nsp > > > _______________________________________________ > juniper-nsp mailing list juniper-nsp@puck.nether.net > https://puck.nether.net/mailman/listinfo/juniper-nsp _______________________________________________ juniper-nsp mailing list juniper-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/juniper-nsp