RE: iSCSI: ISIDs

[Michael Schoberg <michael_schoberg@cnt.com>]

Ultimately, the detection of duplicate sessions has to occur on the target.
If we are not expecting initiators to retain the TSID (target assigned SID)
of any sort between reboots, then something totally initiator based may be
the only fit.  The recurring theme here is how to authenticate the passed
ISID & TSID.  What prevents HBA-B from saying it's HBA-A (or however you
want to word it)?  Putting session identification into the authentication
exchange (and NOT the login header) may be the only way to guarantee
detecting imposters.  If you want to guarantee security along with recovery,
I think this would be the better place to begin.

It appears as though SID needs to act more like the Ethernet MAC address.
We want something that uniquely identifies the initiator whenever it logs
into a target (something larger than 16 bits).  This moves more towards
Marjorie's position that session identification should be pre-assigned to
initiators through configuration:

	... an iSCSI HBA will have to have a configuration interface,
	supplied by the manufacturer, in order to be installed ...

I'm a little skeptical about the dual use of InitiatorName as part of the
session identification.  What prevents a pool of servers from sharing the
same user account credentials (which may be useful in reducing
administration overhead).  It's unlikely that a group of servers would ever
want to share the same session.  Something like "SessionId=" that is
pre-configured on each initiator might work better.