On Jul 5, 2005, at 03:07, The Orange Rider wrote:
It's been suggested to me that this may be for security reasons to make sure that the host isn't using a router that has snuck into the network, or that it might be used to force a host to choose a certain path when presented with equally efficient options on which to send a packet, but I thought I'd check what the IPv6 experts have to say.
I'm not an "expert", but those are certainly the first things that come to mind. (And forget "equally efficient" -- just consider a host with two network connections, finding a router on each. They may not be "equally efficient" paths to the Internet at large, but how is the host to know that?)
There're also "non-broadcast multiple access" link layers where router solicitation might be tricky; I'm not familiar with the details. I think 6to4 is one such; the IPv4 Internet can be treated as your link layer, but you can't send a packet to all IPv4 nodes looking for a router.
Ken