Reduce the Azure vnet address space

Question

Hello Team,

I need to reduce the address space as below at the VNet for one of my project. this vnet also peered with other Vnet. also this vnet has express route and site to site vpn connected. by reducing i will save the ip address which i can use for other purpose. will there be any impact to Azure resources by doing this and any other prerequisite , precaution i need to take. Thanks in advance.

from

10.6.0.0/16

10.7.0.0/16

to

10.6.80.0/20

10.7.80.0/20

also forgot to mention that there is gateway subnet as well currently exist with the ip address 10.6.1.0/24. so if we modify the current address space . will this gateway subnet change automatically to new one or not . if not do i need to delete the gateway subnet and recreate it . and if i have to recreate it that means i need recreate the site to site vpn tunnel as well as express route also ? pls help.

Regards

Jagdish

Answer 1

Hi N Wakchaure, Jagdish,

Welcome to the Microsoft Q&A Platform! Thank you for asking your question here.

this vnet also peered with other Vnet prerequisite

Note: you have to delete all subnets in the vnet.
When you update the address space for a virtual network, you need to sync the virtual network peer for each remote peered virtual network.

refer this link : Update the address space for a peered virtual network - Azure portal | Microsoft Learn

will this gateway subnet change automatically to new one or not.

No

if not do i need to delete the gateway subnet and recreate it . and if i have to recreate it that means i need recreate the site to site vpn tunnel as well as express route also

yes, you're correct.

Thanks,

Rohith

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