nanog mailing list archives
Re: multihoming without BGP
From: "Robert E. Seastrom" <rs () bifrost seastrom com>
Date: Tue, 10 Jun 1997 23:47:39 -0400 (EDT)
Of course, the downsides of using the interface-default hack are: 1) it does not guarantee shortest path for the packets (unless someone has hacked together an lbnamed version that talks to gated and sees which interface has a shorter path to customer <x> based on number of AS hops before it answers the DNS query). 2) It uses a separate address for each interface (not important for a single box, but a room full of boxes, say, 50 of them, 3-way homed at a single site... hmm, that's 100 extra addresses you didn't want to use). I suspect that upstream providers will not be thrilled to hand out more address space if they discover it is being put to such inefficient use. 3) I have not looked at the code, but if it is on a per-interface basis, based on the addresses in the packets, that would seem to suggest that it might not like BSDI 3.0's virtual host scheme (adding IP addresses to the loopback port and then proxy-arping them onto the wire). If this is correct, that would mean you would have to use a different physical machine for each customer. Of course, on this point I'm purely speculating. 4) It puts the onus for fail-over on the DNS server, which means one is going to be using very short TTL. 5) Unless (#1), (#4) implies that fail-over will be manual. Is your Emacs ready to rock and roll on 50 zone files? I admire Paul's hack; it is spiffy for what it is, but I would hardly promulgate it as an advised way to multihome without using BGP. ---Rob
Current thread:
- Re: NSP ... New Information, (continued)
- Re: NSP ... New Information Stephen A Misel (Jun 05)
- Re: NSP ... New Information Michael Dillon (Jun 08)
- Re: NSP ... New Information Tung-Hui Hu (Jun 08)
- Re: NSP ... New Information Bill Manning (Jun 08)
- 192/8 (was Re: NSP ... New Information ) Suzanne Woolf (Jun 08)
- Re: 192/8 (was Re: NSP ... New Information ) Matthew Petach (Jun 08)
- Re: NSP ... New Information George Herbert (Jun 10)
- Re: NSP ... New Information Paul A Vixie (Jun 10)
- multihoming without BGP Tung-Hui Hu (Jun 10)
- Re: multihoming without BGP Paul A Vixie (Jun 10)
- Re: multihoming without BGP Robert E. Seastrom (Jun 10)
- Re: multihoming without BGP Dean Gaudet (Jun 11)
- Re: NSP ... New Information David Holub (Jun 08)
- Re: NSP ... New Information David Holub (Jun 08)
- Re: NSP ... New Information Larry Vaden (Jun 08)
- Re: NSP ... New Information Randy Bush (Jun 08)
- Re: NSP ... New Information Larry Vaden (Jun 08)
- Re: NSP ... New Information Jeremy Porter (Jun 08)
- Re: NSP ... New Information Larry Vaden (Jun 08)
- Re: NSP ... New Information Jeremy Porter (Jun 08)
- Re: NSP ... New Information Edward Fang (Jun 08)