How to block Steam ports with the Netgear N900 WNDR4500

July 11, 2013 No Comments

This is of course, not a review – but still hopefully a source of useful information.  This is a quick guide on how to block Steam traffic on the Netgear WNDR4500.  The same instructions should work on any router if you can replicate what I am showing here.

Blocking Steam Traffic with your Netgear router

The information on this page from the Steam website details the required ports for Steam. By learning which ports need to be open in order to use Steam, we know what ports need to be closed to block it.  The following ports are required:

  • UDP 27000 to 27015 inclusive (Game client traffic)
  • UDP 27015 to 27030 inclusive (Typically Matchmaking and HLTV)
  • TCP 27014 to 27050 inclusive (Steam downloads)
  • UDP 4380

Because the majority of these ports are chronological it makes it a bit easier to block as we can cover off the whole thing with two firewall rules.  Let’s get started!

Open a browser to the IP address of your Netgear WNDR4500 Router or go to and then click on the advanced tab, click on the security menu and then choose “Block Services” from the list that opens up:

Screenshot of services screen on Netgear Router

The Netgear routers don’t have the Steam services listed by default, so we have to add them.  Click on the “Add” button and another window will popup. Fill it in as follows:

  • Service Type: User Defined
  • Protocol: TCP
  • Starting Port: 27000
  • Ending Port: 27050
  • Service Type/User Defined: Steam


And then click add.  The service will be added to the router.  Now we have just one additional service to add, click add again and fill in the details as follows:

  • Service Type: User Defined
  • Protocol: UDP
  • Starting Port: 4380
  • Ending Port: 4380
  • Service Type/User Defined: SteamUDP

Using Netgear to block Steam Traffic

Now that the services have been added you need to make sure that the Netgear router is actually set to block them.

Using the Netgear WNDR4500 to Block Steam


That is it!  You will find if you open Steam that it will start in offline mode and will not be able to connect.  It does not actually stop you launching any games in your library, but the on-line functionality will not work:

Blocking Team Fortress 2 with Netgear WNDR4500


Lulu says

Unfortunately I had to reconfigure our Netgear WNDR4500 because the other Rabbit I live with (Olivander) has developed quite an addition to playing Team Fortress 2 and he is becoming quite boring.  He’s not getting his homework done or doing his daily exercises!  Once he has got his addiction under control, I might consider using the scheduling functionality on the Netgear to allow him a bit of playtime, but I wouldn’t count on it, it’s an outright block for now!

Categories : Misc
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