North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical RE: iBGP next hop and multi-access media
Ok, so correct me if I'm wrong here (I'm just trying to paint a picture of what this thread is trying to conceive), RA-FA1: 10.10.10.1/30, RB-FA0: 10.10.10.2/30, 172.16.16.1/24 secondary? iBGP setup between RA & RB, RB announces to RA with a next-hop of the primary address on FA0, RA announces to RB with a next-hop of the primary address on FA1. When iBGP announces 172.16.16 to RA, you want it announce with a next-hop of 172.16.16.1 as opposed to the primary address 10.10.10.2. Is that right? > -----Original Message----- > From: [email protected] [mailto:[email protected]] On > Behalf Of Ralph Doncaster > Sent: Monday, October 07, 2002 12:56 AM > To: Jason Lixfeld > Cc: 'Alex Rubenstein'; [email protected] > Subject: RE: iBGP next hop and multi-access media > > > > It's a theoretical question. So far I've had one person email > me saying > OSPF can advertise a subnet as local on a shared multi-access > media. If > in fact BGP can't do this, then it's no big deal to me as > nothing in my > network relies on this functionality. > > Ralph Doncaster > principal, IStop.com > > On Mon, 7 Oct 2002, Jason Lixfeld wrote: > > > Are you just asking a question to get a better understanding of how > > things work, Ralph or have you already put this into > production and are > > wondering why it doesn't work a certain way? > > > > > -----Original Message----- > > > From: [email protected] [mailto:[email protected]] On > > > Behalf Of Ralph Doncaster > > > Sent: Monday, October 07, 2002 12:43 AM > > > To: Alex Rubenstein > > > Cc: [email protected] > > > Subject: Re: iBGP next hop and multi-access media > > > > > > > > > > > > My understanding is the route is valid as long as the interface is > > > up; just like adding a secondary IP on the interface. > > > > > > Ralph Doncaster > > > principal, IStop.com > > > > > > On Mon, 7 Oct 2002, Alex Rubenstein wrote: > > > > > > > > > > > Aha. > > > > > > > > So, if you route to a ethernet interface, it will try to > > > arp for that > > > > address on that subnet, even without having a local address > > > on the same > > > > subnet? > > > > > > > > This seems to me to be something you don't want to do. > > > > > > > > Is the entire route valid as long as the router can ARP for > > > one of the > > > > addresses in the routed subnet? > > > > > > > > > > > > > > > > On Mon, 7 Oct 2002, Ralph Doncaster wrote: > > > > > > > > > On Mon, 7 Oct 2002, Alex Rubenstein wrote: > > > > > > > > > > > I've been doing ip route statements going on 8 years > > > now, and I can't > > > > > > imagine why ever -- and how it would even work -- you'd > > > want to ip route a > > > > > > netblock with a next hop of a multi-access brandcast > > > media. As in, the > > > > > > next hop is still truly undetermined. > > > > > > > > > > > > I guess I don't know this because I've never tried it. > > > But, how does the > > > > > > router determine where to send the packets for a route > > > statement as > > > > > > specified above (ip route a.b.c.d e.f.g.h f0/0) ? > > > > > > > > > > When you setup a secondary ip on an interface > > > > > int fa0/0 > > > > > ip address a.b.c.d e.f.g.h secondary > > > > > > > > > > How does it determine where to send the packets? ARP. > > > > > Which is the same as adding the route described above. > > > > > > > > > > -Ralph > > > > > > > > > > > > > -- Alex Rubenstein, AR97, K2AHR, [email protected], latency, > Al Reuben -- > > > > -- Net Access Corporation, 800-NET-ME-36, http://www.nac.net -- > > > > > > > > > > > > >
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