Arch Linux

xzxzxzxz

Member

Registered: 2020-04-20

Posts: 2

Wireguard works on HTTP but not HTTPS

I tried setting up a VPN using wireguard on a debian server and two arch linux and one android clients. On the android client using the official wireguard app everything works fine (HTTPS aswell), however when I attempt to curl a url using https or open it in a browser on the arch linux clients it just loads forever. Meanwhile accessing a url using plain HTTP works fine. Pinging websites etc. works aswell. When curling icanhazip.com I saw that my traffic is indeed going through the server as intended

Arch Linux client:

[Interface]
PrivateKey = ...
Address = 10.0.0.2/32

[Peer]
PublicKey = ...
AllowedIPs = 0.0.0.0/0
Endpoint = ...

Debian Server:

[Interface]
ListenPort = 1194
Address = 10.0.0.1/24, fd42:42:42::1/64
PrivateKey = ...
DNS = 1.1.1.1, 1.0.0.1

PostUp = iptables -A FORWARD -i %i -j ACCEPT; iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE
PostDown = iptables -D FORWARD -i %i -j ACCEPT; iptables -t nat -D POSTROUTING -o eth0 -j MASQUERADE

[Peer]
PublicKey = ...
AllowedIPs = 10.0.0.2/32, fd42:42:42::2/128

[Peer]
PublicKey = ...
AllowedIPs = 10.0.0.3/32, fd42:42:42::3/128

[Peer]
PublicKey = ...
AllowedIPs = 10.0.0.4/32, fd42:42:42::4/128

I am running the standard 5.6.4 Kernel. I'm happy to provide any more information if needed, I just have no idea currently what could be the source of the issue. I'm aware that I'm not binding on ipv6 on the clients currently, I just removed it while debugging so it's not the source of the issue.

Last edited by xzxzxzxz (2020-04-20 16:50:04)

xzxzxzxz

Member

Registered: 2020-04-20

Posts: 2

Re: Wireguard works on HTTP but not HTTPS

Update: Turns out it was MTU related. I had to lower the MTU from the default to about 1350 in the client in the interface section using

MTU = 1350

and it works fine now. It seems like the mobile client finds an appropriate MTU value while the linux one doesn't for me.

mehdi

Member

Registered: 2016-10-05

Posts: 13

Re: Wireguard works on HTTP but not HTTPS

Update: Turns out it was MTU related. I had to lower the MTU from the default to about 1350 in the client in the interface section using

MTU = 1350

and it works fine now. It seems like the mobile client finds an appropriate MTU value while the linux one doesn't for me.

I had the same problem with a Windows 10 client and it had driven me crazy! The Android client would connect with no problem but the Windows 10 would open some website extremely slow and would not open others.

Setting the MTU to 1350 as your suggestion solved the issue. Thanks.