additional ISL for connecting two Brocade FC switches together

[CadenLange]

Hi 

Hi all

I have two old Brocade 5100 switches that are connected via a single ISL. These two switches span across a campus and are about 300m apart. The ISL is single mode.

I i have recently installed two new 6500 FC switches - each new switch is connected to one of the old 5100 switches, so I now have 4 switches in my fabric.

I want to connect the two 6500 switches together with their own ISL (new provisioned single mode). This will mean that the two old 5100's with have an ISL and the two 6500's will have an ISL. Resulting in a ring topology. Is this ok?

I may remove the old ISL in the future.

One consideration is the new ISL will have faster SFPs and therefore negotiate a faster link speed - should I stake steps to ensure both ISLs are are the same speed?

All firmware is up to the latest versions that allow 6500 and 5100 interoperability.

kind regards  C

[NimaG]

Hello CadenLange,

I understand that you are planning to connect the switches in a ring topology

Are the host / storage connections being moved to the new switches as well ?

Performance will be affected depending on the end-device connectivity.

To know the benefits and disadvantages of using specific topologies, please refer: https://support.hpe.com/hpesc/public/docDisplay?docId=sd00001803en_us&page=GUID-D7147C7F-2016-0901-03BB-00000000066E.html

Thanks !

[CadenLange]

Hi @NimaG 

Many thanks for the reply

Yes, the servers and storage have already been migrated to the new switches - there are no servers or storage plugged into the old switches. The old switches just have the ISL between buildings . Once I can move these to the new switches, then I can decommission the old switces altogether. 

We've now decided to completely decommission the old switches. If I simply disconnect the old ISLs the fabric will segment and some servers\storage will lose connectivity - to avoid this I was hoping to be able to connect the new ISL to the new switches before I remove the old ISL. In doing this it will create a ring topology for a few minutes before I disconnect the old ISL. I wanted to make sure this is a valid approach.

Thanks

[NimaG]

Hello CadenLange,

Thanks for clarifying.
Ideally, when a new switch is attached to an existing fabric, the zoning information is propagated to the new switch, as a result of the merge.

Reference: https://techdocs.broadcom.com/us/en/fibre-channel-networking/fabric-os/fabric-os-administration/9-2-x/Administering-Advanced-Zoning-AG/v26772637/v26771295.html

Verify the configuration on the new switches. If all is good, the old switches may be disconnected and decommissioned.

Regards,
Nima

[CadenLange]

@NimaG Again, thanks for the info.

So the new switches are all installed and zoning has propogated without error - that's all good. All the devices have been repatched to the new switches and, again, that's all gone smoothly without issue.

My remaining taks is to move an ISL that currently connects to two sites through the old switches. I have a brand new ISL installed that I want ot use as it is faster than the existing ISL.  I will connect this new ISL to the new switches and then I can fully decommission the old switches.

My question is can I connect the new ISL to the new switches before I disconnect the old ISL from the old switches?

thanks

[NimaG]

Hello CadenLange,

Yes, you may connect the new ISL to the new switches.
Once again, verify that the configuration is stable, before removing the old ISL.

Regards,