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LearnEverything
34 Posts
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4757
August 9th, 2018 06:00
MDS - Disconnecting ISL
Hello,
I have a fabric containing two Cisco MDS 9513 switches. I would like to get rid of one of the switches in the fabric and to do so I need to get rid of the ISL between them.
My question is can this somehow affect the other MDS in the fabric that is supposed to stay?
4090
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Posted August 12th, 2018 05:00
We do have full zoneset distribution enabled, but do not use IVR.
4090
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Posted August 13th, 2018 10:00
ok, so IVR topology to clean up. I can't think of anything that could be causing issue when you shutdown one of the 9513s.
4090
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Posted August 13th, 2018 13:00
So in your opinion I can safely disconnect? What about principle/slave, does it matter or not because of full zone distribution?
4090
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Posted August 14th, 2018 13:00
principle/slave ..does not matter, it will figure it out on its own without any impact. I wanted to double check on full zone set distribution to make sure you have a full copy of zoneset on each switch.
4090
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Posted August 14th, 2018 22:00
Great, thanks.
Just out of interest, why did you ask about IVR, how can it impact the ISL disconnection?
4090
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Posted August 16th, 2018 04:00
I see. Isn't it easier though 2 have those MDSs in a fabric, configure the same VSAN for the ISL and have full zone set distribution rather than enabling IVR?
4090
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Posted August 16th, 2018 04:00
i don't think that would be any impact per say but i like to clean up "relationships" while devices are still online
for example here is sample IVR topology
# show ivr vsan-topology
AFID SWITCH WWN Active Cfg. VSANS Switch-Name
-------------------------------------------------------------------------
1 20:00:00:0d:ec:f0:12:40 yes yes 20,30
1 20:00:00:0d:ec:f0:11:00 * yes yes 10,30
these two switches are located at two different facilities, about 15 miles apart, connectivity is provided via DWDM. There is a VMAX array at each site and they need to be able to SRDF to each other so we need to make sure RDF adapters can talk to each other. RDF ports at site A are in VSAN 20 and in VSAN 10 at site B. So to provide communication between these two distinct VSANs we create a brand new VSAN 30 on both switches that will merge and create this "virtual" bridge between these two switches. VSAN 30 is called "transit" VSAN. When we define IVR topology we specify what VSANs can travel on top of this virtual bridge. So I like to clean up while this bridge is still online where i can clearly see what is what and where, personal preference.
4091
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Posted August 16th, 2018 11:00
Best practice is not to merge fabrics that span multiple datacenters. If my DWDM link starts flopping and I have one VSAN, it will impact systems at both locations. With transit VSAN systems at both locations are isolated and it may impact RDF traffic. You don't want fabrics to start merging and un-merging ..flip flop is not good.
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Posted August 17th, 2018 01:00
How about interconnecting 2 different fabrics through two switches (one at the edge of each datacenter) and just having the same VSAN for the interconnection link with FCIP. In that case I wouldn't need IVR and at the same time I could have DR, don't you think?
dynamox
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4086
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Posted August 11th, 2018 21:00
if full zone set distribution enabled, are you using IVR ?