For more details, please see ourCookie Policy.

Fibre Channel (SAN)

Frequent Visitor
Posts: 1
Registered: ‎07-22-2016
Accepted Solution

Cascaded FICON over the XISL unable to pull CUP data.

[ Edited ]

Dear Board,


I am expecting following undocumented problem.

We have cascaded FICON consisting of 4x Brocade DCX 8510 with full license pack (FICON CUP installed).


Problem description:

When we generated FICON Director activity report or run /d m=switch($$$$) for the CU's which are remote (accessed through XISL) for LAPR which has the CUP devices configured we receive empty records. For two devices which are local to the lpar everything is reported fine.


We have the support case opened with IBM however I am keen on conclusion that CPU data cannot be pulled through XISL this is not documented despite I have read all possible documentation about the CUP (there is not a lot of it).


For the switches with problems FICON reports UAM bits as:


0        1      1     0         1     0


Aybody else faced this problem before? Or can confirm the above?


"We’re all mad here. I’m mad. You’re mad."
"How do you know I’m mad?" said Alice.
"You must be," said the Cat, "or you wouldn’t have come here.”
Broadcom Moderator
Posts: 106
Registered: ‎03-29-2010

Re: Cascaded FICON over the XISL unable to pull CUP data.

[ Edited ]

I think I know what your asking, and not sure if you are seeking info on the cascaded FICON data traffic itself, or the management access of the FICON port within the Brocade switch(in-band management)?


In either case, the way the FICON director(emulated in the switch) requests that information is with an RNID command(Req Node ID Data) which is a FICON specific command, and is not supported or recognized by the standard FC protocol. Therefore, you are trying to gather information on FICON specific info over an XISL.


The Brocade switch in logical switch mode, with logical switches configured does not use XISL for ANY FICON traffic, including commands in FICON. The CUP info can only be sent or received over a local ISL which is logical switch to logical switch, ISL. The best documentation I can give you is chapter 10, table 47 of the FOS Admin Guide:


FICON Up to two logical switches per chassis can run FICON Management Server (CUP), but the
FICON logical switch must use ISLs and not XISLs.


Followed by a further restriction down in the restriction on XISLs section of chap 10:


Following are restrictions on XISL use. XISL use is not permitted in any of the following scenarios:
• The logical switch is intended for use with FICON.


Bottom line is XISL does not support FICON at all, in any way shape or form. The protocol tools aren't there, and that includes the ability to process the RNID req from the FICON Director(which translated your d m=(switch) command).


Best of luck,


Any and all information provided by me is for entertainment value and should not be relied upon as a guaranteed solution or warranty of mechantability. All systems and all networks are different and unique. If you have a concern about data loss, or network disconnection, please open a TAC service request for service through Brocade, or through your OEM equipment provider. If this provided you with a solution to this issue, Please mark it with the button at the bottom "Accept as solution".

Join the Broadcom Community

Get quick and easy access to valuable resources across the Broadcom Community Network.