Traffic forwarding issue between vnetA (azure vpn gw) and vnetb

Question

Hello,

I would like to ask about the issue which I have a problem to solve.

I set up Azure vpn GW in vnetA and successfully set up l2l with on-prem. When I created the server in subnetX in vnetA, I can ping on-prem resources via the l2l tunnel. When I created vnetB and managed peering between both vnets. I didn't receive the packet back to the server in vnetB, but when I ran tcpdump on the on-prem server I could see sending packet to the server in vnetB and in logs on the on-prem VPN I saw that this communication is going to the tunnel, but the issue is the packets never come back to the server in vnetB.

Any hint of what I am missing or what I do wrong?

Answer 1

Hi,

Please confirm that you have gateway transit settings configured properly on the peerings. Article below details the settings for each peering. When reading the article, "Hub-RM" is your vnetA and "Spoke-RM" is your vnetB.

Configure VPN gateway transit for virtual network peering

https://learn.microsoft.com/en-us/azure/vpn-gateway/vpn-gateway-peering-gateway-transit

If you are unsure about something please add a comment below with details/screenshots and I will assist.

Thanks.

-TP