For the separation access of local and external resources i`m used a caching DNS my mikrotik.
sample:
My external address : 195.195.195.10
my hostname 1 : test.com + http://www.test.com, located in server 1
Server 1 address: 10.10.10.2
my hostname 2: blabla.test.com, located in server 2
Server 2 address: 10.10.10.3
Mikrotik Address: 10.10.10.1
To customers located inside the firewall gained access to the server without going through mikrotik,
i made the following mikrotik dns records:
Static: 10.10.10.3 blabla.test.com
Regexp: 10.10.10.2 (.*)?.test.com
It was found that in version 5.x version regexp records became a higher priority than static records.
Customers using the Mikrotik DNS server (10.10.10.1) when request domain blabla.test.com receive IP address 10.10.10.2
In version 4.x it works properly, static entries have more weight and do not overlap regexp records.
Now, we have to make all versions of subdomains, that is very inconvenient.