RA & DHCP problem...

[Phil Mayers]

On 30/12/2013 21:40, S.P.Zeidler wrote:
> Thus wrote Phil Mayers (p.mayers at imperial.ac.uk):
>
>> One problem we have with this setup: If two devices are on a port,
>> in different IPv6-enabled VLANs, they both see both RAs, and IPv6
>> connectivity breaks.
>
> I assume you have considered fixing the route part by using fe80::1
> (f.e.) as router address on all relevant VLANs?

In fact we use a consistent HSRPv2 config on all our subnets, so the 
gateway *is* always the same; not fe80::1 but fe80::5:73ff:fea0:1. So 
basically, yes we did this.

> What reason spoke against it?

As above, none ;o)

> You'll still have the "using wrong prefix to source packets" problem
> though (which could be fixed using dhcpv6 if your equipment were inclined
> to support it).

Sure. I guess I should re-check, now that we're on IOS 15SY; maybe they 
finally fixed the bug - I did eventually get them to acknowledge that 
looking up the DHCP server next-hop and getting an output interface of 
Null0 and a source IP of fe80::... was a bug, not a feature request :o/