Server Information
Blue Flag servers are ran 24/7 and you can usually find them by looking up "Blue Flag" in the DCS server browser and choosing the map you wish to play on. Alternatively you can connect by IP as shown below.
Server IP's
Caucasus:
Persian Gulf:
SRS
SRS (Simple Radio Server) is used by Blue flag as its main method of communication between pilots.
Note: using SRS is not an enforced requirement, but highly encouraged. You can find the latest version of SRS here: https://github.com/ciribob/DCS-SimpleRadioStandalone/releases/latest
Caucasus: srs2.flag.blue:5002
Persian Gulf: srs1.flag.blue:5014
Alternatively, you can also just open your SRS client and connect to Blue Flag in DCS, the SRS AUTOCONNECT feature will make sure you're connected to the correct server.