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Re: addition of TLV to locator ID or locator ID set



On 3-okt-2005, at 23:38, Erik Nordmark wrote:

As I understood it, a host would configure its IPv6 address as today (stateless, DHCPv6, etc). And the shim proxy would form a HBA parameter set (based on the prefixes assigned to the site) for each host and run a 1:1 NAT. In that case the host doesn't know which IPv6 address the proxy has picked for it.

I would rather avoid that... Although the harmful effects of the NAT could be limited to legacy communication if the shim is established immediately and the remote end is informed that we use an identifier that's different from the locators.

Or where you thinking that the host could only use DHCPv6 and the shim proxy and the DHCP server would coordinate things so that the host is informed of its shimmed addresses?

Although configuring non-shim hosts with a specific address (with the correct HBA interface identifier) is somewhat difficult, this is an operational problem that can be solved in a variety of ways using standard system administration approaches. While having a NAT in the middle requires changes from applications to work through the NAT, which is much, much harder to accomplish.

You wouldn't need split DNS for the shim6 site-intermediary case AFAICT, because the locator addresses would never be reachable - only the mapped address would ever be a valid address to try reach.

You mean you assume it is ok to publish unreachable addresses in the DNS?

If address policy mechanisms work well, this shouldn't be an issue: try unique site locals first if they match our /48, last if they don't. But currently, address policies aren't implemented widely and mechanisms to automatically adjust them not at all, AFAIK.