[Pana] IESG discussions on draft-ohba-pana-relay

[Jari Arkko <[e-mail]>]

We discussed this draft today. The remaining Discuss was about how 
mandatory we should make IPsec. You had discussed about a SHOULD with 
Stephen. I suggested that while interoperability is useful and 
mandatory-to-implement mechanisms are good for it, we also have to talk 
about how much value we bring with a security mechanism. In this case 
there are some issues like MITMs able to block PANA packets. However, 
some of these vulnerabilities are not helped by relay - PAA security, as 
the relay can still do bad things, and because ARP/ND vulnerabilities 
between the client and relay in any case make it possible to become a 
MITM. Stephen had some suggested text that I agree with:

"PRE/PAA security is OPTIONAL since PANA messages are designed to be 
used in untrusted networks, but if cryptographic mechanism is supported, 
it SHOULD be IPsec."

Jari