[radvd-devel-l] Router advertisement and forwarding on client side?

Pekka Savola pekkas at netcore.fi
Tue Mar 20 11:06:24 EST 2007

On Tue, 20 Mar 2007, vincent.trucmuche wrote:
> In a LAN where router and "configuration server" would be
> separate machines, router could "announce" itself as "default
> gateway" using RA w/o prefixes and the "configuration server"
> could announce ONLY prefixes using RA w/ "router lifetime" to
> 0 (telling it is not a default router). DHCP will provide
> other informations (DNS, NTP...).

OK, but it isn't clear why you would want to have a separate 
configuration server.  AFAICS, that doesn't buy you anything; 
there is benefit only if your default router isn't capable of 
advertising some specific configuration option.  I haven't seen this 

>> Just Prefix Information options?  Are you suggesting that radvd 
>> will be able to start in non-forwarding mode if the configuration 
>> includes 'AdvDefaultLifetime 0' and no more-specific route 
>> statements? If yes, are you willing to create a patch that does 
>> this cleanly?
> If you are OK to add this patch to radvd I will provide it to
> you. :)

If the patch is clean enough, I'm willing to seriously consider 
including it.

>> As far as I understand, DHCP-PD will set up the routing for the 
>> delegated prefix (on the upstream side) and the default route (on 
>> the downstream WAN interface).
> I don't think so. There is nothing in RFC 3633.

Even if there isn't, you may want to examine how other vendors have 
deployed solutions like this.  After all DHCP-PD has been deployed to 
some degree..

Pekka Savola                 "You each name yourselves king, yet the
Netcore Oy                    kingdom bleeds."
Systems. Networks. Security. -- George R.R. Martin: A Clash of Kings

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