Impossible to add a network to a template

[Nightstick]

Hi everyone ,

it's a completely  miss-understanding for me , 

When I try to add a network to a template , I got this issue : 

Failed to auto-generate 1 unique subnet for VLAN 'Default': subnet pool '/24 from 172.X.X.0/16' has 0 subnets available.

But I've checked again and again and I'm sure that i still have some available network slot range. 

I can create a new network without template with no  issue , and configure the auto vpn on it .

I've only encountered this issue with all my templates

Can anyone give me the solution ? 

best regards ,

[RWelch]

Sharing these links, maybe they will help guide you.
MX Templates Best Practices 
Managing Multiple Networks with Configuration Templates 

[Ryan_Miles]

You'll typically get that error when a hub is advertising a supernet through the VPN Local Networks section. Basically, to avoid this your hub needs more specific advertised routes that won't conflict/overlap with spoke subnets.

[Nightstick]

I already have 22 networks, some in templates,
I've already checked a lot, if there's an overlap, I can't create other networks by authorizing the new network to go up on the vpn within the same organization.
However, I can do it outside the template.
and why now?

[Ryan_Miles]

Did you add a new hub with a subnet that overlaps with the template subnet?

[PhilipDAth]

If you look in the route table:

Do you definately see "spare" routes?

Are there any other routes using a similar prefix, 172.x.x.0/24, but with a number that is different from /24?

[Nightstick]

yes , i've some /22 and /24

but on the same 172.Y.X.0 only my X change , but i'm sure that i've a lot of slot available , it's not my first branch in a template

[jimmyt234 · Accepted solution]

I've encountered this before and it has been due to a similar/bigger CIDR prefix being routed via a NMVPN peer.

[Nightstick]

Like a default gateway 0.0.0.0/0 ? in nmvpn ? 

[Nightstick]

of course , the cause was a default route 0.0.0.0/0 in my NMVPN.

I will open a ticket to the meraki support because now it's a issue for me , how to route the traffic to my Secure web gateway without it ?...

[jimmyt234]

During a maintenance window you remove the 0/0 route via the NMVPN peer, this should let you then create your networks, after which you can put the 0/0 route back in.