I've recently moved to PN, having suffered with Sky for 10 months after they took over O2, however that's all in the past now.......
I run a relatively (for a home) large LAN with a variety of devices connecting to it running differing O/S: Windows (7&8), Ubuntu, iOS and Synology DSM 5.0.
Pretty much all but the iOS devices are connected via gigabit ethernet, although some of the Win 7 laptops occasionally connect via wi-fi. All relevant O/S updates have been applied to all machines and all the windows machines run the current version of Avast! (2014.9.0.2021). Firewalls are turned on with default settings (Windows own flavour on the respective machines and ufw on the Ubuntu machine)
Here's the problem. From time to time (there is no set pattern), the WIn7 machines will fail to connect to the internet - chrome gives the standard "connecting" message in the bottom left corner of the window. However I can connect to any device on the LAN without problems. When the Win7 machines are internet-less, the Win8 one is fine, as is the Ubuntu machine and the Synology box.
The Win7 "issue" can last anything from 10s to 30 minutes and will go as suddenly as it appears. During this time disabling Avast! has no effect, neither does flushing and renewing the DNS cache. Wireshark does not show anything untoward in the datagrams between the Win7 devices and the Router (a TP-Link W8970) and replacing the router with the PN Technicolour one makes no difference. Although I have 20+ years experience in IT and telecomms, I was never a datagram guru so I might have missed something - any Wireshark experts out there that can suggest some monitoring filters to apply / or what to look for?
The network connection logo in the taskbar will also show the orange exclamation mark and report "no internet access" during the outages.
Thanks, in advance, for your help.
plusnet FTTC ~ 30.7 / 16.6 @ 565m