RA for a different router

[Tore Anderson]

* Alexander Clouter

> I probably missed the memo but *why* would you want to send the default 
> gateway in a DHCPv6 response when the local network topology would 
> *know* far more accurately what is going on.  Especially when you 
> consider gateway failover and that in theory you do *not* need
> anything like VRRP/HSRP as the glue to do this.

* Nick Hilliard

> RA gateway fail-over takes $client_ra_timeout seconds for clients to
> realise that the gateway has disappeared, where $client_ra_timeout is
> substantially greater than $ra_announcement_interval (probably by a
> factor of at least 3 in order to cope with packet loss, etc).
> Typically, $ra_announcement_interval will measured in seconds, possibly
> tens of seconds.  This leads to fail-over times of tens of seconds to
> possibly minutes.   vrrp / hsrp / glbp will typically provide fail-over
> in an order of magnitude less time.

I too would prefer using VRRP to a failover mechanism depending on RA
information being quickly timed out on the hosts.  But what is gained by
using DHCPv6 for configuring the default gateway/virtual router, compared
to simply announcing it in a standard RA packet?

Best regards,
-- 
Tore Anderson
Redpill Linpro AS - http://www.redpill-linpro.com/
Tel: +47 21 54 41 27