Hey Ori, could you check to see if this still happens in the latest Steam client update?
Sorry for the late reply - right around the time you posted this my laptop's display broke off and the integrated keyboard lost a few working keys and the external keyboard wouldn't work (did I mention the extended warranty lapsed two weeks ago?
) - I am certain Steam used some of their secret powers to do that
That said: I just now tested it, things I did for those so inclined as to repeat the stuff:
1) Started Steam client in
online mode and allowed it to update itself and the game that is installed.
2) Set it to
offline mode
3) Restarted the computer
4) Started Microsoft Network Monitor 3.3
5) Set it to capture network traffic
6) Started Steam client
7) It asked to start in offline mode and asked the firewall to permit network access.
8) Started it in
offline mode and allowed it network access
9) It talked (up- and download) with IP address 72.165.61.190
10) Repeated 3-8: it talked with server 69.28.153.82
11) Repeated 3-8: it talked with server 87.248.196.194
Things noticed:
The update did change the behavior. Previously it talked to 2-3 servers at the same time, now it only talks to one. Previously the exchanged packages were of fixed width and about 2-3 times the current total size. Now they are of varying width but the total transferred information is only 30-50% of the previous size and up- and downloads seem to be similar in size. The download size doesn't seem to have changed much the upload size is reduced.
Comparing it to online mode: the behavior in online mode prior to entering the user password is almost exactly what it was in offline mode prior to this update.