Copypasted articles for the simplest scenario are everywhere… Finally I managed to figure out the stuff. It’s not easy to find Skype for Business DNS Requirements for multiple Edge pools. Skype for Business DNS Records requirements Skype for Business Internal DNS Records Description If you are not using “split-brain” DNS you can create a zone for each required DNS records pointing it to the internal IP-address. Thus Skype for Business clients will get information only from their zone, so if external client is trying to connect to Skype for Business server, it will resolve the entries to the external IP-addresses, if it’s from internal network then it will resolve the DNS entries to internal IP-addresses using the internal DNS server. The DNS is often deployed as “split-brain” DNS deployment: the same zone name is deployed internally and externally but with different (internal or external) IP-addresses for the same entries.
Skype for Business uses two types of DNS records: A record and SRV record. Skype for Business DNS Records are one of critical components of the whole infrastructure.