Template Deployment with Duplicate "UNIQUE" Subnets

[Fernando_AR]

 Hello Everyone!

I am preparing to deploy meraki on a few locations, i am on a Test-Lab Phase.

I found something strange that i want to share with you and check whats going on...

I have a Network Template to deploy some MX65 devices, we use 5 VLAN on each site, and i´ve choosed UNIQUE Subnets from a pool for each VLAN.

I notice that i was assigned same subnets on some of the MX65 that i deployed ... is not allways the same VLAN, it looks like random... 

As this is a Test lab, the MX are not powered all the time, so i was wondering, how does Meraki determine if a subnet is free from the pool or it´s already in use in other Network? it does this with the information on the Dashboard or by looking at the Rountig table of AutoVPN???

Thank you all...

Fernando.

[NolanHerring]

It's from your ORG dashboard from what I've been told, so the devices don't need to be online for them to pull up subnets they'll grab

If you give it say 10.10.0.0/16 and you want it to assign /24's to each subnet from that pool, it will be random

One VLAN might show 10.10.33.0/24 and another might show 10.10.222.0/24

Key being that the system should never assign a subnet already in use.

Are you saying that you ARE seeing that?

[Fernando_AR]

Yes, definitively ...

This is only one example, it happened randomly on other vlans and between different locations. 

Example: 

Network ANetwork BAddressingUnique Selected

[NolanHerring]

Shot in the dark here, but how many sites do you have using that /23 broken into /27s ?

Your limit is 16, so if you have 17 sites, it's possible that might be the issue

Otherwise, as far as I know, this might be a bug? Have you contacted support yet out of curiosity?

[Fernando_AR]

Thanks Nolan!

At the moment I have only 6 Networks...

I will contact support, my first reaction was the community as I imagine if this really works this way, it would probably appear on any bigger deployment...

[PhilipDAth]

>If you give it say 10.10.0.0/16 and you want it to assign /24's to each subnet from that pool, it will be random

Correct.

[NolanHerring]

@Fernando_AR  Have you reached out to support. Curious if they gave you any feed back yet.

[Fernando_AR]

Yes I did, seems like we hit a bug.

They say it´s a known issue, still under investigation and they attached my case under a parent case... nothing more at the moment.

[NolanHerring]

Thanks for the update. Feel free to post back here if you hear anything else as others such as myself will be curious 😃

[Sean_Born]

Did support find a fix for this?

We are having the same issue and they still have not found a fix and its been over a month.

[Fernando_AR]

No, No response yet... 

What I´ve done so far is to manually change the duplicated subnets, when do it so, you do get the alert that subnets are duplicated...

[Fernando_AR · Accepted solution]

Hello All. Cisco said that this is now Fixed. i was not able to test it as our deployment was already completed.