Weird Network Freeze Issues

I'm trying to diagnose an intermittent problem with the networking on a particular computer, and I have found a string I think I can pull to unwind the problem...but I don't know where to go from here.

The computer is a Windows 8.1 platform, wired to my home Internet.

The problem I am having is this: at random intervals, for about two minutes at a time, the network interface will freeze; usually I notice this when I try to load a web page, and it stops on "Resolving host...". I've tried different DNS servers, and I can always access the same DNS server from another computer on the local network without problems.

I've tried various malware and virus removal tools, and none of them can find anything wrong.

I have noticed, running "netstat -o -n" on a command prompt, that a new entry appears consistently when the network freezes, and is not there when things are running normally. It's very different from all the other ones (which are originating from either the loopback or the IP address of the local terminal). The line reads like this:

I'm unfamiliar with this, I've never seen an IP address like that. Some of the literature I've read suggests it has to do with IPv6, but that hasn't helped me resolve it.

Can someone give me some insight into what I should be looking for next? I'm pretty much stumped now.