Spot on Gert ! + also including static routes. That's why as some of you for sure remember static to multiaccess interfaces say /8 without giving explicit next hop are very dangerous ;)
On Thu, Jan 31, 2019, 09:57 Gert Doering <g...@greenie.muc.de wrote: > Hi, > > On Thu, Jan 31, 2019 at 10:51:01AM +0200, Saku Ytti wrote: > > On Thu, 31 Jan 2019 at 10:34, Robert Raszuk <rob...@raszuk.net> wrote: > > > > > As mentioned on the other thread decent routers should resolve peer's > IP to mac when creating FIB adj and building rewrite entries. > > > There is no "first packet" notion nor any ARPing driven by packet > reception. This should apply to p2p adj as well as p2mp - classic LANs. > > > > > Are you guys saying that say MXes don't do that ? > > > > I'm not sure what you are saying. I must misunderstand, but are you > > saying once I configure /8 LAN, router ARPs all of them periodically > > until the end of time, retaining unresolved, resolved cache for each > > of /8? Which router does this? > > I think Robert is talking about router-to-router LANs, where you have > "prior knowledge" in your FIB. > > Like, OSPF neighbours, or BGP next-hops pointing to LAN adjacencies - so > the router could go out and start the ARP process the moment it learns > "I have a next-hop in BGP pointing to <lan interface>:<ip>". > > (I think it would be a great thing to have, especially including a > feedback mechanism "ARP / ND failed, this next-hop is invalid!" to BGP - > solve a number of blackhole problems with indirect BGP routes) > > getr > -- > "If was one thing all people took for granted, was conviction that if you > feed honest figures into a computer, honest figures come out. Never > doubted > it myself till I met a computer with a sense of humor." > Robert A. Heinlein, The Moon is a Harsh > Mistress > > Gert Doering - Munich, Germany > g...@greenie.muc.de > _______________________________________________ juniper-nsp mailing list juniper-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/juniper-nsp