Fluctuating Wireguard Speed w/ GL-iNet Flint over Xfinity

VPN
1

I’ve got a bunch of variables in play here so it’s hard to pin down what’s actually causing the problem, but maybe this group can help…

I recently got a GL-iNet Flint router after my poor Slate burned out from running WireGuard 24/7 (RIP). I have it connected via Ethernet to my Xfinity modem/router, set to a static IP with that address added to the DMZ in the Xfinity router.

Sometimes the connection speed through WireGuard is almost as good as my raw internet speed, about 200Mbps. But it’ll frequently crater, down to closer to 3-4Mbps, and won’t recover for sometimes hours. Sometimes when I disconnect the VPN and then reconnect it, it’ll start the speedtest super fast and then immediately start falling, like something just noticed I was on a VPN and started throttling. And if I turn the VPN off, it immediately returns to normal.

I’ve checked ProtonVPN’s server list when this happens and confirmed the server I’m connecting to isn’t overloaded. The router’s app shows it’s not overtaxed either. I’m assuming it’s Xfinity, but they aren’t going to be any help here. Is there a port or something I should open in the Xfinity router to get around whatever is throttling it? Any suggestions?

2

Just in case anybody digs this up later looking for an answer to the same question: I turned off the AdGuard functionality built into the router OS and that cleared up the problem. It looks like using that and the VPN was a bit much.

3

Which servers do you have configured?

4

I have the config files for US-VA#28, 30, and 33 uploaded to it. Some have all the NetShield options turned on, some don’t.