I am connected to the Transact network, and use a D-Link ethernet router to connect to the internet. Having left the router on when the computers were off, there was still a large amount of download (about 5 MB in a 5 hour period). Is this traffic typical? I am now disconnecting the router from the broadband connection to terminate the session and avoid unnecessary downloads. Can I configure the router to terminate when the PC is off, or is there a better strategy?

Traffic from a router which has no active computers is not normal. Since the computers have been turned off, but data download has continued, we can assume there isn’t an issue with the computers themselves. Where did you obtain the download information: from the router status, or from your ISP’s account management site? If you obtained the information from the router status, then I suggest you logon to your ISP’s account management site and check the usage on their system. This will help eliminate a false count on the router. If the ISP site shows that no data has been downloaded in the period the router reports the 5 MB download, then it seems the router is giving a false indication. Reasons for this could involve perhaps the data count on the router includes the data that is transferred between the computers and router itself, in addition to counting traffic in/out of the WAN (Wide Area Network i.e. broadband) interface.

However, if your ISP also reports usage during this period then it seems the router is doing something over the internet connection. Check whether the router has an automatic update feature and ensure this is disabled, to prevent the router from downloading updates without your knowledge. Unfortunately you cannot tell the router to turn off when the computers switch off, since the design of broadband routers are to be always-on and to establish an internet connection when required by one of the networked computers. You can setup the router to disconnect the internet connection after a certain period of inactivity, but this is unlikely to fix the problem, since if the router needs internet access itself it will just re-establish the connection. The only real way to prevent this is either switch off the router (or unplug, if the device doesn’t have an off switch) or disconnect the broadband cable from the router. Unfortunately I don’t have any other suggestions, but contact me again with information on the data download the router reports, compared with the data download your ISP reports, then we may be able to further narrow down the problem.