6125XLG in IRF - multiple chassis over mix of SFP+ and QSFP+

[Michal Doležal]

Hi, very simple question.

I would like to create new IRF ring-topology to join two enclosures together. Now I have two 6125XLG in IRF over internal downlink ports (IRF daisy-chain) (4x10G) so 40G line exist between switches.

I would like to add second chassis with pair of 6125XLG switches to the IRF to create ring.

Inside chassis 6125XLGs will be connected using downlinks port (4x10G), but both enclosures together using 2x40G ports (ring-topology), so Switch A to Switch B (4x10G), Switch B to Switch C (1x40G), Switch C to Switch D (4x10G), Switch D to Switch A (1x40G).

Is this intermix of 10G and 40G supported? From my point and documentation yes, but none of the topologies in documentation shows this.

[sdide]

Hi Michal, 

From the R2306-HP 6125XLG Blade Switch IRF Configuration Guide

http://h20566.www2.hpe.com/hpsc/doc/public/display?sp4ts.oid=5404487&docLocale=en_US&docId=emr_na-c03931778

"To connect blade switches in different chassis into an IRF fabric, you must use the SFP+ and QSFP+ ports on the switch front panel. To connect blade switches in the same chassis into an IRF fabric, you must use the downlink 10-GE Ethernet ports on the switch rear panel. These ports are invisible to users and do not require physical cabling"

So this is what you're doing. And...

"You can use a QSFP+ port as an IRF physical port, or use the using tengige command to split a QSFP+
port into four 10-GE interfaces. "

Yes, so far so good.

"When you use the SFP+ ports on the switch front panel as IRF physical ports, follow these guidelines:
• The SFP+ ports are grouped by port index into two 4-port groups. One port group contains ports
5, 6, 9, and 10. The other port group contains ports 7, 8, 11, and 12. If you use one port in a group
for IRF connection, you must also use all the other ports in the group for IRF connection. However,
you can bind them to different IRF ports.
14
• Before you bind an SFP+ port to an IRF port or remove it from the IRF port, you must shut down all
the SFP+ ports in the same group. "

You don't use these, but this is still good info for those who plan to do so.

"When you use the downlink 10-GE Ethernet ports on the switch rear panel as IRF physical ports, follow
these guidelines:
• If you use one of the downlink 10-GE Ethernet ports for IRF connection, you must also use all the
other downlink 10-GE Ethernet ports for IRF connection. However, you can bind them to different IRF
ports.
• Before you bind a downlink 10-GE Ethernet port to an IRF port or remove it from the IRF port, you
must shut down all the other downlink 10-GE ports on the switch rear panel. "

I think they mean the 4 downlink ports connected to the other switch, otherwise the above makes no sense. Also binding these 4 physical links to more than one IRF port doesn't really make sense since you have only one other switch to connect to inside the bladecenter.

all in all - you're good.

Regards

[Michal Doležal]

After long time but better to write this here.

Finally we made this using all 10G ports. So all around 4x10Gbit. Downlinks using 10G ports and also chassis interconnection using 4x10Gbit SFP+ cables.

I asked HPE directly and answer was simple. Intermixing of 40G and 10G in IRF is not recommended. Problem can be in balance between 10G ports. For example communication goes from switch 2 to 3 so over 40G line to 4 and then over 4x10G to 3.

Important is result. HPE recommendation for HPE 6125XLG is to use 10G only or 40G only IRF connections.