I thought you might be interested in looking at What port to open for dedicated server?.
https://forums.bohemia.net/forums/topic/80629-what-port-to-open-for-dedicated-server/?do=findComment&comment=1384966
× Pasted as rich text. Restore formatting
Only 75 emoji are allowed.
× Your link has been automatically embedded. Display as a link instead
× Your previous content has been restored. Clear editor
× You cannot paste images directly. Upload or insert images from URL.