OpenVPN Client on Router Causes Some Sites to Load Very Slowly

[Goobi]

I am running the latest Merlin firmware on a 68U. I am using the OpenVPN client on the router using PIA VPN as the provider. I am using policy based routing to route a small subset of clients through the VPN. Most of the clients are mobile devices with a couple of light use laptops.

My problem is whenever I have the OpenVPN client started the clients using the VPN load certain sites very slowly. It almost seems like they are waiting for some request or requests to timeout before loading the page. This is causing these sites to be unusable since each click on any of the sites takes 1-2 minutes to load.

The websites I am seeing this issue on are:

snbforums.com
nydailynews.com
drudgereport.com
space.com

If I turn off the VPN client on the router these site load quickly as expected. If I turn on the VPN these sites take a couple of minutes to load but any other sites load quickly. If I turn on the VPN client directly on a device that is configured to use the VPN client the sites load right away. Not sure if this suggests that there is a problem with the VPN client on the router. Also, I see this problem regardless of the PIA server I use on the VPN client on the router.

Any suggestions on what I could look at to troubleshoot this issue? Thanks in advance for any guidance.

 

[john9527]

What operating system on the clients? What browser? Is IPv6 active? What type of IPv6? Are you using PIA's nameservers or a different set?

I also run PIA and don't see any problems.

 

[Goobi]

What operating system on the clients? What browser? Is IPv6 active? What type of IPv6? Are you using PIA's nameservers or a different set?

I also run PIA and don't see any problems.

Hi John. The clients are iOS 9 and one Windows 7. I got a Mac and android phone using this VPN service as well but I have not tried on those devices yet. I am using Safari and Firefox on the iOS and Windows laptop. I use IPv4. I am using opendns for the name servers as I use dnscrypt and domain filtering. The accept dns configuration field is disabled in the client config. I also have global filtering set to router to force all clients to use the configured dns on the router. Do you think this may be related to what is happening? Thanks

 

[john9527]

@Goobi - My first thought is that it sounded like a 'Happy Eyeballs' problem (basically trying to reach an unreachable IPv6 site), but you are IPv4 and none of the sites you listed look like they are IPv6 enabled, so scratch that one.

It does sound like it may be related to DNS however. So one thing you may want to try is setting the VPN DNS option to Strict and see if it changes things (this will force it to try the PIA DNS server first).