Meraki Community

NeilB · ‎May 10 2019

Hi,

We currently have a number of different deployment templates for the MX's we have in our estate, and we have each template to assign a number of unique /24 subnets from a /16 subnet for each VLAN.

We are looking at deploying some Z3 devices which obviously a /24 subnet for 3 VLANs for example is way over the top.

What i'm wondering is, if we are wanting to deploy an additional template for the Z3 devices only with /28 subnets for each vlan from the same /16 range as the other templates above, will this cause issues for any subsequent /24 range that will be issued for the non z3 templates?

e.g.

Non Z3 Template

VLAN100 - 10.0.0.0/24

VLAN200 - 10.0.1.0/24

VLAN300 - 10.0.2.0/24

Z3 Template

VLAN100 - 10.0.3.0/28

VLAN200 - 10.0.3.16/28

VLAN300 - 10.0.3.32/28

Is the Subnet issuing smart enough to realize that the 10.0.3.0/24 subnet is partially assigned?

Hope that makes sense and sorry if this sounds stupid.

Cheers

Neil

PhilipDAth · ‎May 10 2019

I don't know the answer.

What I believe happens is that when a subnet is chosen it consults the AutoVPN routing table for the Org to see if the subnet is free first. If this understanding is correct then you will be fine,

jdsilva · ‎May 10 2019

I also don't know the answer... But I would like to. This is an interesting question. Following this.

http://blog.brokennetwork.ca |

@jdsilva

Aaron_Wilson · ‎May 11 2019

Yea, it would be nice if Meraki could chime in. If the AutoVPN/headend/org tracks and dictates which subnets are free this could be some good information for us all. Right now I have my templates with their own summary, but if a single summary could be shared across multiple templates....

Mr_IT_Guy · ‎May 13 2019

You should have no troubles trying to accomplish this. I am currently using the same summarized subnet across 4 templates. @PhilipDAth is correct in that the AutoVPN routing table is consulted to see if the subnet is available.

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NeilB · ‎May 15 2019

Hi All,

Thanks for the posts. It does seem to be all fine with the mix between /24 and /28's.

I guess as you are unable to make a full /24 from a subnet that has a /28 already assigned, the dashboard will just issue the /28's from the remaining subnets that can't be used to make the /24s.