Azure IPv6 load balancing backend port conflict with IPv4 load balancing backend port

Question

I have an Application running in Azure VMs on TCP port 80. The VMs are dual stack and listens on both IPv6 and IPv4 addresses.

I configured a Azure load balancer to forward the traffic from internet to the VMs.

Ipv4 load balancing rule uses front-end port 80 and backend port 80. I tried to add IPv6 load balancing rule - front-end port 80 and backend port 80, since i want to enable both IPv4 and IPv6 support for my single application. But I got error since backend port 80 running on TCP is already used (for IPv4 rule)

If this is a restriction in Azure Load balancer part, what is the workaround or standard implementation scenario, to make the Load balancing IPv6 traffic reaching the application (here port 80)

Answer 1

This should work because both rules use a different address family. Please make sure you are expressing your rules correctly so that an IPv6 rule is applied to an IPv6 VIP and and the IPv4 rule is applied to an IPv4 VIP.

If that is the case already, please open a ticket with support to investigate.

PS: If it's possible to include the actual commands used to configure and the verbatim of the error message, I might have more insight to offer.