While building your virtual network, you might need to consider the following points:

• You cannot add the following address spaces to your virtual network:
  • 224.0.0.0/4 (multicast)
  • 255.255.255.255/32 (broadcast)
  • 127.0.0.0/8 (loopback)
  • 169.254.0.0/16 (link-local)
  • 168.63.129.16/32 (internal DNS)
• You cannot connect virtual networks that have overlapped address spaces
• As a default limit, you can create 50 virtual networks per region per subscription, but it can be increased up to 1,000 virtual networks if you contact support
• As a default limit, you can create 1,000 subnets per virtual network, but it can be increased up to 10,000 subnets, if you contact support
• As a default limit, you can have 4,096 private IPs per virtual network, but it can be increased up to 8,192 if you contact support