Any Reason for Virtual WAN Hub Larger Than /23?

Question

I've seen in the FAQ for Virtual WAN that the recommended hub network size is a /23. Are there reasons to go any larger (/21, /20, etc)? Is there a rough estimate of how many vnets / how much traffic a /23 hub will accommodate? Thanks!

Answer 1

@Alex K

Welcome to the Microsoft Q&A Platform. Thank you for reaching out & I hope you are doing well.

I understand that you would like to know the reason for recommending /23 address space size for a vWAN vHUB.

Please note that vHUB is not a traditional VNET.

• Technically, a vHUB will not accommodate other VNETs.
• Instead, a vHUB can only be linked/connected to other VNETs.
• The limit for this is generic and is not dependent on the vHUB address range/size.
• Refer : Virtual WAN limits
  • 

As stated in the FAQ, What is the recommended hub address space during hub creation?

• A /24 address space should work (minimum)
• The /23 recommendation is to compensate for any future product feature releases that may require this.
• You can go with an address range bigger than this, such as /22, provided you have the network range available in your scenario (not overlapping anywhere else).
  • However, the recommended /23 range should do the trick.

Kindly let us know if this helps or you need further assistance on this issue.

Thanks,

Kapil

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