Port Control Protocol (PCP) Server Selection
RFC 7488
Yes
No Objection
Note: This ballot was opened for revision 08 and is now closed.
(Ted Lemon; former steering group member) Yes
(Adrian Farrel; former steering group member) No Objection
(Alia Atlas; former steering group member) No Objection
(Alissa Cooper; former steering group member) No Objection
"If the PCP client has exhausted all IP addresses configured for a
given PCP server, the procedure SHOULD be repeated every fifteen
(15) minutes until the PCP request is successfully answered."
Is there something that prevents a client from re-trying this procedure endlessly for a server whose whole set of IP addresses remains unresponsive? Phone call to tech support? ;)
(Barry Leiba; former steering group member) No Objection
(Benoît Claise; former steering group member) No Objection
(Brian Haberman; former steering group member) (was Discuss) No Objection
Thanks for addressing these issues.
(Jari Arkko; former steering group member) No Objection
(Joel Jaeggli; former steering group member) No Objection
(Kathleen Moriarty; former steering group member) No Objection
I support Stephen's comments and think the SecDir reviewer recommendations would be helpful.
(Martin Stiemerling; former steering group member) No Objection
(Pete Resnick; former steering group member) No Objection
(Richard Barnes; former steering group member) No Objection
I support Brian's DISCUSS points, especially the one about one vs. multiple PCP servers. If the client doesn't know which case it's in, it can't really follow these procedures.
(Spencer Dawkins; former steering group member) No Objection
In this text:
1. A PCP client should construct a set of candidate source addresses
(Section 4 of [RFC6724]), based on application input and PCP
[RFC6887] constraints. For example, when sending a PEER or a MAP
with FILTER request for an existing TCP connection, the only
candidate source address is the source address used for the
existing TCP connection. But when sending a MAP request for a
service that will accept incoming connections, the candidate
source addresses may be all of the node's IP addresses, or some
subset of IP addresses on which the service is configured to
listen.
2. The PCP client then sorts the PCP server IP addresses as per
Section 6 of [RFC6724] using the candidate source addresses
selected in the previous step as input to the destination address
selection algorithm.
if I'm understanding this, if multiple PCP clients end up with the same list of candidate source addresses. and then sort the same list into the same order, does that mean they'll tend to select the same IP addresses that have sorted to the front of the list, even though the PCP server has multiple IP addresses, or will something I'm not seeing cause a more balanced load distribution?
Perhaps there are reasons why that's OK, but I thought I should ask ...
(Stephen Farrell; former steering group member) No Objection
- I don't get how one can really ensure the restriction below is satisfied, nor why it's needed. (I do get that some setups will be able to check that.) " o The configuration mechanism must distinguish IP addresses that belong to the same PCP server." - The secdir review [1] also makes a resonable point that explaining the risk (here) of Nonce re-use would be good. [1] https://www.ietf.org/mail-archive/web/secdir/current/msg05355.html