RE: FCIP: Comment 120

["Murali Rajagopal" <muralir@cox.net>]

Mallikarjun:

There is some text in FC-BB-2 (Clause 13.2. 3)  that may also add some
calrity to the discussion of sharing IP address:


" The FC-BB-2_IP Reference Model supports one logical IP Interface and
allows sharing a 4-byte IPv4 or 16-byte IPv6 address in the following ways:

a)A single IP address per FC-BB-2_IP device
  - A single IP address shared by all FC/FCIP Entity pairs
b) Multiple IP addresses per FC-BB-2_IP device
- A single IP address per FC/FCIP Entity pair
c) Multiple IP addresses per FC/FCIP Entity pair
- A single IP address per VE_Port/LEP pair

Use of two different IP address schemes at the two ends of an FCIP Link is
not expected to cause inter operability problems."

-Murali

-----Original Message-----
From: owner-ips@ece.cmu.edu [mailto:owner-ips@ece.cmu.edu]On Behalf Of
Mallikarjun C.
Sent: Wednesday, May 08, 2002 10:16 AM
To: roweber@acm.org; ips@ece.cmu.edu
Subject: Re: FCIP: Comment 120


> I would think that sending a TCP connect request to the same IP Address
> and Port as was used in the previous TCP connect request would achieve
> the intended result.

Not a correct assumption.  You are using names (FC Fabric Entity WWN is
a name.  The FC/FCIP Entity Identifier is a name unique within the scope of
the FC Fabric Entity.) in FSF only because IP addresses/TCP port
associations
cannot provide the FCIP-end2end assurance that the right entities are
talking.

Besides, I don't see anything in the current document that prohibits
multiple
FC/FCIP Entity Pairs from sharing the same IP/TCP address/port - and I
believe
that is the right architectural approach.
--
Mallikarjun

Mallikarjun Chadalapaka
Networked Storage Architecture
Network Storage Solutions Organization
Hewlett-Packard MS 5668
Roseville CA 95747
cbm@rose.hp.com


----- Original Message -----
From: "Ralph Weber" <ralphoweber@compuserve.com>
To: <ips@ece.cmu.edu>
Cc: "Mallikarjun C." <cbm@rose.hp.com>
Sent: Wednesday, May 08, 2002 6:26 AM
Subject: Re: FCIP: Comment 120


> "Mallikarjun C." wrote:
>
> > Upon further thought, it appears to me that the "Destination FC/FCIP
> > Entity Identifier" should be sent and received in the FSF.  I can not
> > think of a way currently to build an FCIP_LEP with multiple FCIP_DEs
> > - for ex., how would a sender indicate his intention to add a TCP
> > connection to an FC/FCIP Entity Pair that it's already communicating
> > with?
>
> I would think that sending a TCP connect request to the same IP Address
> and Port as was used in the previous TCP connect request would achieve
> the intended result.
>
> The only alternative would be to REQUIRE SLP interrogation before every
> TCP connect request, and even then there would be zero assurance that
> the IP universe would not shape shift between the SLP activities and
> the TCP connect request.
>
> Surely, there is some stability in IP addressing.
>
> Thanks.
>
> .Ralph
>
>