FCIP link merging fabrics or using IVR

[bastiano42]

                   Hi everyone, this is the situation:

I need to connect 2 Cisco MDS9509 through an IP WAN for mirroring 2 storage IBM 4800. The 2 sites are not far (1 mile) but are connected through a 300 Mbps IP WAN shared with other applications. The 2 fabrics are not too large, both are using just VSAN1 and have 12 double path server each and 1 storage device, only the 2 storages should communicate.

What the best practice would be, to merge or not to merge the 2 fabrics using IVR and a transit vsan? What would be cons and pros?

Thnx in advance.

[Abhi Varada]

I have a similar problem. We have two data centers about 200 miles apart and we have a 300 Mbps IP WAN between them. I have created an FCIP link and tunnel but the problem is, now both fabrics are merged. The VSANS themselves are isolated (because we have only allowed 1 vsan through the FCIP tunnel)  but the device-aliases are all merged. I mean device-aliases which have been created on either fabrics now have been merged to both the fabrics now and DCNM sees switches from both the Data centres as one huge fabric now. I am not sure how to separate the fabrics. I atleast want the device-alias databases separate from each other. Any help is much appreciated. 

[bastiano42]

I am not very into fiber channel but I am pretty sure that if you disable the fcip link everything should come back as before. If you don't want to merge the fabrics you have to create a transit vsan and assign it to the fcip interfaces and add ivr with or without nat depending by possibly overlapping domain ids. That's how I managed to connect the 2 storages. Hope it'll help.

[Walter Dey]

Anytime FCIP is used over private or public IP cloud, it is highly recommended to use IVR, avoiding any flapping merge/breakup fabric situation.

see my other comment: https://supportforums.cisco.com/discussion/12156556/how-create-fcip-link-without-merging-fabrics

[Abhi Varada]

Thanks a lot bastiano42 and wdey for your comments. Definitely helps understand further.

[Abhi Varada]

Guys, a follow up question. When I do create an IVR, do I enable IVR just on both the switches with the FCIP link or on all switches in the fabric? Or does that not matter?