I'm not sure if this is a lan, vodafone or ipad problem so hopefully its in the right forum.

We were dropping our kids off at my parents for the holidays and when we connected the kids ipad mini's to their wireless network every device on the network could no longer access the internet, regardless of whether it was connected wirelessly or cabled.  My parents are on a vodafone connection using a vodafone supplied router and there was also a samsung phone and windows 8 laptop on the network.   The router shows it is still connected to the internet but nothing on the network can even connect to google.  As soon as I disconnect the Ipads the other devices can then access the internet without doing anything else.  I tried connecting one ipad at a time but that resulted in the same issue.

Does anyone have any ideas what might be causing this.

Thanks