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June 23rd, 2009 12:00


Hi team.

Please brief me about FLOGI and PLOGI, and how it works.


November 17th, 2009 14:00


Lots of good technical details in the links above. Here is a summary.

N_Port: an end device connecting to a switched fabric network, such as a SCSI initiator or a SCSI target.

F_Port: a port on a switch that provides access to Fabric Services (eg. the Fabric Nameserver & the Fabric Login Server etc)

Fabric_point_2_point initialization (ie. N_Port to F_Port initialization) involves the following ordered sequence: FLOGI, PLOGI, PRLI.

    •           N_Port requests a unique 24-bit address from the Fabric Login Server (accessible via an F_port on a Fabric switch).
    •           N_Port informs the Fabric Name Server of its personality and capabilities. For example:
          • WWNN, WWPN
          • Buffer credits for flow control
          • clock frequency ('speed capability')
          • Upper layer protocol support (eg. SCSI-3, IP)
  • PRLI
    • Upper layer protocol communication. Well, ever since SCSI was designed and engineered (1970s, or so, previously SASI...), SCSI initiators need to discover SCSI targets. So, during PRLI, N_Port SCSI initiators discover N_Port SCSI targets (which is an opportunity for the host (maybe a UNIX host) to assign a target ID to the device path).

  •      Depending on the OS, you may be able to investigate further with commands like:
      • egrep -i 'flogi|plogi|prli' /var/adm/messages    

Thought for the Day. How completely is SCSI ?  It's had a few makeovers, but maybe we should now call it BCSI . Hats off to the SCSI developers !!!

8 Posts

July 9th, 2009 08:00

Try this...other explanations are available - and I have NO attachment/bias to IBM - it was just the top of the Google search

November 5th, 2009 14:00

I moved this thread into the ControlCenter community, since it was on the ControlCenter welcome page.  I am not sure that is the correct community for it, so please let me know what the intended community was for this question.

It does look like the information provided in  the links above and does answer the question, but if not, please let us know.

2.1K Posts

November 13th, 2009 13:00

Hey Candi, This probably fits better over in the Proven Professional Community. Once the Forums move here it would likely have fit better there, but for now it doesn't relate much to ControlCenter.

790 Posts

November 17th, 2009 13:00

Ok, we've moved the thread.  Let's see if anyone in EMC Proven Professional has input.

November 17th, 2009 13:00

Ok, I will see if I can move it there.  Thanks, Allen.  It occurred to me after I moved it in here, that there was the possibility the person could not see it in the ControlCenter community unless he was a CCOC member.  Proven Professionals is open.

I cannot move it there, as I do not have access to move it in.

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