Re: [secdir] [Isms] secdir review ofdraft-ietf-isms-transport-security-model-12

[Jeffrey Hutzelman <[e-mail]>]

--On Tuesday, May 05, 2009 01:50:46 PM -0400 David B Harrington 
<[e-mail]> wrote:

> That is a deployment decision made by an administrator who has an
> understanding of what is appropriate to the system in question. MUST
> is for implementers and SHOULD is for deployers.

Nononono.  When we say "MUST is for implementors", we mean that our 
specifications give requirements for implementations which claim to comply; 
RFC2119 requirements language is generally inappropriate for deployment 
advice.

It is appropriate to say TSM MUST be use with a TM that provides 
appropriate security; that is equivalent to saying that implementations 
MUST NOT use TSM together with an inappropriate TM, such as UDP.


That said, selection of transport and security models generally is an 
operational decision.  TSM itself is really architectural glue to allow us 
to push some of the security infrastructure down into a transport below 
SNMP, such as SSH or TLS.  You'd never say "I want to use TSM, now which 
transport should I use"; you'd say "I want to use SSH -- oh, for that to 
work, I have to use it with TSM".


-- Jeff