(usagi-users 00492) Re: Routing question

[Nathan Lutchansky <lutchann@xxxxxxxxxx>]

On Mon, 7 May 2001, Wang Kai wrote:

> Coudl an IPv6 router advertise an indicate route to the local subnet
> through router advertisement(RA)? For example, one IPv6 router wants to
> leak a route to fec0:0:ff00::/64 to the local subnet so that all nodes
> in the subnet could add this route into their routing table
> automatically. I mean a to-net route, not a default route.

This is not possible.  Router advertisement messages can only be used to
establish default (0/0) routes on hosts.  See RFC 2461 for more
information on what can be in a Routing Advertisement message.  If you
need to establish more complicated routes, you should either configure
them manually on each machine (not recommended) or use a routing protocol
like RIPng on each network.

On the other hand, it is not necessary for all of your hosts to have
specific routes to each network.  When a host attempts to send a packet
through the default router, the default router will issue an ICMPv6
redirect, which will cause the host to send the packet to the correct
router instead.  So your hosts will still be able to talk to all of your
subnets, even though they don't have routes for all of them.  -Nathan

-- 
+-------------------+---------------------+------------------------+
| Nathan Lutchansky | lutchann@xxxxxxxxxx |  Lithium Technologies  |
+------------------------------------------------------------------+
|  I dread success.  To have succeeded is to have finished one's   |
|  business on earth...  I like a state of continual becoming,     |
|  with a goal in front and not behind. - George Bernard Shaw      |
+------------------------------------------------------------------+