[111554] in North American Network Operators' Group
RE: v6 & DSL / Cable modems
daemon@ATHENA.MIT.EDU (TJ)
Sat Feb 7 11:56:46 2009
From: "TJ" <trejrco@gmail.com>
To: <nanog@nanog.org>
In-Reply-To: <20090206181545.GE5164@isc.org>
Date: Sat, 7 Feb 2009 11:54:52 -0500
Errors-To: nanog-bounces@nanog.org
>What most people do of course is VRRP.
Sure, or HSRP or GLBP ... all still doable.
>
>Barring that, you just specify multiple default routers, and the client
will
>select the router that still responds to ARP. But support for this is not
>universal, so.
Indeed, not universal and in fact default behaviors vary wildly.
>
>When that isn't available, what I have done in the past here is to use the
>DHCP server to give out a default router option that is sorted according to
>the DHCP relay agent that was used to reach the server (keyed on giaddr
>contents).
>
>The net result is that the client uses the default gateway which it used to
>reach the DHCP server, and so will automatically receive an updated value
if
>that router fails, as part of DHCP lease rebinding (it will reach the
server
>via the alternate router).
Which I think is pretty slick.
OOC - between the "router fails" and "I renew/rebind my address", is the
host down and out?
So you are accepting either a noticeable outage or tweaking your
lease times, yes?
