SRV record conflict between on-prem SfB server and Teams

[Newlife]

Hi Community,

One of our customer currently has Teams tenant and the required DNS records in Public DNS. But there are some higher officials accounts requires on-prem SfB server for security reasons.

Customer would like to enable SRV records in on-prem for automatic sign in, external sign in etc. They don't want to create hybrid deployment.

The reason is we need create the SRV record, _sipfederationtls_tcp.contoso.com pointing to on-prem Access edge for external signin.

Similarly we need to create the SRV record for online Teams signin pointing to sipfed.lync.online.com

Questions:

1.Is there any conflict on SRV records required for on-prem external, automatic sign in and Teams users sign in ? (Because we don't have hybrid deployment but the domain is same for on-prem and online, but there is no hybrid, split domain,  for example Contoso.com)

2. Will public DNS accept two similar entries (_sipfederationtls) one for on-prem and another one for Teams tenant?

Any guidance would be of help. Many thanks!

[#2]

Hi @Newlife ,

Not a direct answer to your specific query but I am concerned by the reason of using SfB on prem over Teams.

I would argue that Microsoft would be able to secure any infrastructure better than any single business but that is subjective I suppose.

Back to the DNS point, I can only recommend that you follow official Microsoft guidance. As to be honest if you are wanting to make use of On Prem and Cloud technologies that is 100% the reason for Hybrid deployment options and to do otherwise, working or not, is going to probably be unsupported and a big business risk because of it.

https://docs.microsoft.com/en-us/skypeforbusiness/plan-your-deployment/network-requirements/dns

Thanks

Henry