What IPs to map for subnet routing in Traffic Manager

Phil 1

I've set up a Traffic Manager Profile that uses the subnet routing method to 2 endpoints. One is an Azure Web App, the other is a Public IP (with a DNS tag name) attached to an Azure Virtual Machine. With no subnet routing I can access them both so the endpoints are definitely set up fine.

This doc says to add the end user IP to traffic manager, which I've done and can't get the routing to work. This doc however says to use the IP address of the recursive DNS that is used - I don't know the outbound IP of my ISPs DNS and don't expect my customers to either. I've put in the IPs of the DNS servers in traffic manager and that doesn't work either.

I want to use this feature to route customers based on their outbound IP to one of two endpoints, have I missed the point and am trying to use the technology incorrectly?

Thanks

SaiKishor-MSFT 17,201 Reputation points

2021-09-22T14:11:44.187+00:00

@Phil Thank you for reaching out to Microsoft Q&A. I understand that you are having issues with Azure Traffic Manager setup where you want to setup Subnet Routing to 2 endpoints.

As mentioned in the doc, for Subnet routing settings:

Add the IP address of myVMEastUS test VM. Any user query originating from this VM will be directed to the myTestWebSiteEndpoint.

As per this doc, you need to add the IP address of the machine from where the query is originating i.e., the Public IP of the source machine. Is this the IP that you tried to add to the Traffic Manager Profile? You can know your Public IP by going to https://whatismyipaddress.com/

Regarding the second doc where it talks about adding the recursive DNS resolver, I am looking into this further and will update you soon. Looking forward to your reply. Thank you!
SaiKishor-MSFT 17,201 Reputation points

2021-09-24T08:54:59.733+00:00

@Phil Please let me know if you have any further questions and we will be glad to assist further. Thank you!