I'd say you just didn't block it properly, I mean it has to access the interwebz somehow.

How exactly have you told your Windows firewall to block Steam?
Have you specified a rule for a program and selected the steam.exe? Because that's what I did and as far as I can tell it's working. If I just put Steam into offline mode I can still use the "store" and "community" tabs in the client. So offline mode isn't really offline. But once I block the steam.exe I get "Error Code: -138" on both tabs and updates to the client don't appear to be happening unless I manually reconnect.

If you have done the same thing however, I should probably dig a little deeper and see if it's not somehow still sneaking through...

:) Not really but I like to find things out and clarify the question of the original post.

Thanks for all the great advices. I will try it out!

That's exactly what I did. I went to the firewall, then to advanced settings, then to inbound and outbound rules and then modifying all rules having Steam in the name to be blocking. I might check this to make sure I did it right.

I did the same and had the same problem. The only way I could fix it is by going to Windows Firewall Properties and then the Private Profile tab and then setting "Outbound connections" to "Block".

Only trouble with that is I now have to explicitly add rules to allow every single program I want to connect to the internet. Which may not be a bad thing I suppose.

I understood what he said. My point is there is a difference between noticing the internet is there and using it versus requiring that internet be there.

A real test would be to literally have no internet connection on the PC for an extended time period, which is impractical for a ton of reasons. Like I said previously though I had Steam in offline mode for 5+ months before and it ran fine. It never updated either, I know this because I used a laptop USB satellite modem which had very limited bandwidth and and a monthly cap, and I would have noticed if it did.

Hm, in offline mode it does still contact "http://api.steampowered.com/ISteamUserAuth/AuthenticateUser/v0001/" to authorise your account when you start Steam. Other than that it doesn't seem to contact the internet unless you tell it to do something. So you can still use the store or manually check for an update of the steam client, but it doesn't seem to do it automatically (at least it hasn't for me, yet).

Also I note that in "offline" mode "http://api.steampowered.com/ISteamUserStats/GetGlobalAchievementPercentagesForApp/v0001/?gameid=&format=vdf" gets called when you click on game details. Presumably this gets the global achievement percentages.

The Steam Offline Mode article says that to use "offline" mode you have to have played your games at least once and they have to be up to date. What happens when there is a game update and you're in "offline" mode? Will the game stop working after awhile?

I agree but if you manage to properly block outgoing internet traffic from steam.exe using a firewall then you don't have to deny all internet traffic to your PC.

If you are 'properly' offline - how would Steam and the game know that there is an update waiting?

Well if you're properly offline it may decide to lock access to your games after a certain amount of time until you go online again. This might explain why some people say that steam stops working but others have gone 5+ months in "offline" mode.

This is pure speculation at the moment. I might test it but obviously it'll take time...


EDIT: It seems that if I exit steam and put my clock two weeks ahead then open steam again then it needs to reauthenticate me. This might just be because it somehow detects I've tampered with the clock. The only way to be sure would be to use a firewall to block its internet access for two weeks but otherwise use it as normal.

impractical for you. A way of life for others.

My nephew just built his first ever (with my supervisions) and was so excited about having his first PC (he owned and played a PS3) and was a huge Skyrim and Black Ops 2 fan.

Both Steam games.

My sister's family lives in a rural area, where there is literally NO wired internet available . None through Verizon, none through cable companies, NONE period. She has some sort of internet service that is very slow, has a real small download limit (10GB I think) and after that becomes as slow as dial-up, LITERALLY.

Only had the PC a couple of weeks now and is already a Steam hater.

I'm so proud.

Fuck Steam and any other company that makes it likely that I or you or anyone else can't PLAY GAMES THAT THEY FUCKING BOUGHT AND OWN.

Fuck Steam. Again.

So I got the borderlands 2 season pass and thought I would go and shoot some stuff in the face. After doing the whole download of the DLCs (I had the base game installed already) I put steam on offline mode and launched the game.

"Steam servers are too busy to handle your request"

Dafuq?

Can't say I blame the steam haters.

Steam needs an active connection the first time you run a game after installing or updating it (DLC apparently counts for this). Similarly, you can't install a game from a retail disc or Steam's own backup feature without an internet connection even if you've previously installed that game on that same computer and Windows installation.

This is all part of Steam's DRM-centric design; just because you aren't a pirate now doesn't mean you won't be one later...

Yeah, well, I still would expect a message saying "you need to connect to the internet" while on offline mode, rather than "servers are busy"

I used to be a pirate, it's things like this that make me want to put my eyepatch again.

I think Punkbuster also starts even when in offline mode. Now that really doesn't make sense...

Steam's offline mode applies to the client, not the games themselves. Games that use Steamworks for multiplayer integration will see the offline state and act accordingly but all other games are unaware of Steam's offline state as are any bundled third-party components (PunkBuster, Uplay, etc.)

Similarly, any game sold on Steam that requires its own online DRM check every time you launch it (rather than using Steam's own implementation) won't work without internet access regardless of whether Steam itself is in offline mode.