[secdir] Secdir review of draft-ietf-p2psip-rpr-11

["Klaas Wierenga (kwiereng)" <[e-mail]>]

Hi, 

I reviewed earlier version 10 (http://www.ietf.org/mail-archive/web/secdir/current/msg04256.html), I didn't get any response and the security considerations don't seem to address what I wrote at that time, so I'll repeat:

--
Hi,

I have reviewed this document as part of the security directorate's ongoing effort to review all IETF documents being processed by the IESG.  These comments were written primarily for the benefit of the security area directors.  Document editors and WG chairs should treat these comments just like any other last call comments.

This document defines an optional extension to RELOAD to support Relay Peer Routing (RPR) mode (as opposed to Symmetric Recursive Routing (SRR). The document is straightforward and clear, but with respect to the security considerations a few comments:

- I am surprised that there is no discussion on the relay peer being the single (or few) point of failure,  and thus becoming an interesting target for DoS attacks: the relay peer acts as a hub for all traffic coming from the peers that have it as their relay. Especially when there is a limited number of relays it becomes attractive to bring the relay down. 

- The other thing I wonder about is why there is the need to trust the relay, why is this different from the DRR case (apart from the observation in my previous comment)? It seems that the system would work just fine without the explicit trust in the relay peer, in fact, the way I understand it every peer in the overlay can in principle act as a relay peer (I imagine a scenario where the relay peer acts as the "established connection").

Cheers,

Klaas Wierenga
--