Subject: [pcp] proposal: PCP server discovery

From: "Dan Wing" <[email-masked]>
Date: Wed, 23 Mar 2011 18:02:13 -0700

We've had some discussions on resurrecting the idea of using an
IANA-assigned address for the PCP server, which is
http://trac.tools.ietf.org/wg/pcp/trac/ticket/8.  

I have a proposal which I believe resolves everyone's concerns, which is to
change the text from -
An idea is to change the existing PCP Discovery routine from this (which is
currently in -07):

OLD:
   1.  if a PCP server is configured (e.g., in a configuration file or
       DHCP), that single configuration source is used as the list of
       PCP server(s), else;

   2.  the address of the default router is used as the PCP server.

NEW:
   1.  if a PCP server is configured (e.g., in a configuration file or
       DHCP), that single configuration source is used as the list of
       PCP server(s), else;

   2.  the address of the default router is used as the 
       first PCP server, and the IANA-assigned PCP server address 
.......^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
       is used as the second PCP server.
.......^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

As with today's operation, the PCP-aware routers can receive UDP 
messages sent to its internal interface.  The functionality would 
allow PCP messages to be routed upstream (towards the Internet) if 
there is a PCP-unaware router on the path.  If the default router
doesn't respond to the PCP messages, the PCP client will time out
after ~30 seconds of attempts and try sending messages to the 
IANA-assigned address.

(Dave Thaler mentioned this was discussed during a PCP interim, but
I couldn't find a mention of such a discussion in Paul Selkrik's
notes at http://www.ietf.org/mail-archive/web/pcp/current/msg00981.html
or http://www.ietf.org/mail-archive/web/pcp/current/msg00885.html)

-d