Getting empty responses from certain sites

[jonmwalton 0]

I have got a Netgear DM200 modem connected to Zen Internet. It is currently set up to use their DNS servers.

 

This is hooked up to a Netgear R7000, which has DD-WRT installed and the VPN configured and connected successfully.

 

For some reason I cannot access www.myfitnesspal.com while connected to the VPN. It returns and empty response.

 

I have had the same problem when trying to submit this post while connected to the VPN. It returned an empty response.

 

Every other site I have tried is fine so far.

 

I have checked the route to www.myfitnesspal.com and it checks out fine. All green.

 

Any tips on what might be wrong or how to debug?

 

 

[jonmwalton 0]

Support fixed this for me by asking me to add the mssfix property and setting it to 1350. Actually I was able to increase it to 1440 and the problem was resolved. It was caused by large packet sizes and the mssfix property allows them to be broken up into smaller pieces.