two shim6-esd-00 comments

[Pekka Savola <pekkas@netcore.fi>]

Hi,

Two smaller comments, probably already made, on 
draft-nordmark-shim6-esd-00.txt:

1) this obviously requires control over the reverse tree, which is by 
no means given for generic shim6 audience, though it might be more 
popular with sites which want to employ rewriting.

      The shim performs the identifier to locator lookup very similarly
      to normal IPv6 reverse lookups (form a query name based on the
      nibbles in reverse order and append ip6.arpa), but it queries for
      SRV records.

2) In the latter part of the example below, AFAICS, are you able to 
use the Sent Locator immediately?  This could be part of a 3rd party 
[bombing] attack?  Does it need to be probed first or is this 
sufficiently secure as it is?

      B processes the I1 message as specified in [7] to generate a R1
      message.  In addition, it copies the content of the Sent Locator
      Pair option into a Received Locator Pair option.  Host B must
      decide whether it should send the R1 message to the IP source
      address of the R1 message, or send it to the potentially different
      Sender Locator in the Sent Locator Pair option in the I1 message.
      Once B has made this decision, it puts the addresses, in this
      example <B1, A2> in the IPv6 header as well as into a Sent Locator
      Pair option.


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