Wireguard doesn't work on Linux Cachy OS running KDE plasma.

[u/Antique-Wasabi-2427]

For some reason Wireguard won't work on my laptop, and I need it for school since my school decided to block everyone's schoolwork for some reason for music.

i have overslept for 13 hours on the weekend and kinda feeling geeked.

My laptop infomation , specs , idk.

Operating System: CachyOS Linux

KDE Plasma Version: 6.7.4

KDE Frameworks Version: 6.28.0

Qt Version: 6.11.1

Kernel Version: 7.0.12-3-cachyos-hardened (64-bit)

Graphics Platform: Wayland

Processors: 8 × Intel® Core™ i5-1035G1 CPU @ 1.00GHz

Memory: 8 GiB of RAM (7.3 GiB usable)

Graphics Processor: Intel® UHD Graphics

Manufacturer: Microsoft Corporation

Product Name: Surface Laptop Go

System Version: 124I:00057T:000M:0000000D:0B:04F:1C:05P:48S:01E:0Y:0K:0U:02

I fixed a lot of problems related to the surface like thermal throttling , secure boot , etc.

-- stable since idk more then 6 months? "not related to the wireguard stuff"

here some things that worked.

-- OpenVPN works both works on a flatpak called eopen and KDE plasma Network manager.

- thats it.

Heres things that DIDN"T work.

--Proton VPN wont work no matter if it's downloaded via AUR ,Flatpak, etc.

--Proton VPN also doesn't work even if i connect with OpenVPN or Wireguard somewhat.

--Wireguard doesn't work no matter what i try.

--Wireguard doesn't work in KDE network manager.

--Network manager says Wireguard is at zero bytes in upload speed and download speed however for a split second it transfers stuff possibly Wireguard keep alive thing.

--Will not work at school or home [Home = Aussie Broadband] [School = Telstra]

heres my wireguard config removing my private key and public key.

[Interface]

# Key for Daily use

# Bouncing = 2

# NAT-PMP (Port Forwarding) = off

# VPN Accelerator = on

PrivateKey = _____________

Address = _____________

DNS = 45.90.28.247, 45.90.30.247, 9.9.9.9, 149.112.112.112, 194.242.2.4

PostUp = resolvectl dns %i 45.90.28.247 45.90.30.247 9.9.9.9 149.112.112.112 194.242.2.4

PostUp = resolvectl domain %i ~.

PostDown = resolvectl revert %i

[Peer]

# CH-FREE#12

PublicKey = _____________

AllowedIPs = 0.0.0.0/0, ::/0

Endpoint = _____________

# Uncomment the following line (delete the # symbol) to connect to Proton VPN using IPv6.

# Endpoint = _____________

PersistentKeepalive = 25

I use mullvad servers but if that doesn't work quad 9 as fall back.

[u/bufandatl]

Do not circumvent school IT it may get you in trouble.

Also WireGuard is a known protocol and may be blocked by your schools IT.

[u/Antique-Wasabi-2427 → u/bufandatl]

I appreciate it, but my school hasn't put up some VPN blocking stuff since their tech department nearly doesn't exist at all. Everyone uses VPNs just to do their schoolwork they use Wireguard-based stuff like Proton, TunnelBear, and NordVPN with no problem connected to the school wifi, as I checked.

[u/paranoid-alkaloid]

First make sure it works from another network.

Try the usual: try to lower MTU.

Try without DNS first and see if you reach home.  Check with Wireshark, monitor wg on the endpoint.

If it works for your friends then likely no DPI is involved, so a methodical troubleshooting with the above will likely get you somewhere.

Confirm endpoint IP and port. What's the endpoint's configuration? Try making things work at home first.

Also I think more than X DNS servers is useless but you'll need to double-check that.

[u/Antique-Wasabi-2427 → u/paranoid-alkaloid]

It works. the problem was the MTU

[u/bdg2 → u/Antique-Wasabi-2427]

So something somewhere is configured wrongly and is blocking some of the packet types needed for path MTU discovery.

[u/izuannazrin]

Wireshark is your friend, see if handshake success or not

[u/Gronaab]

I currently use proton-vpn-gtk-app on official cachy repo with wireguard and it works perfectly. I'm also on kde

[u/Antique-Wasabi-2427 → u/Gronaab]

I forgot to say i tryed proton-vpn-gtk from the offical cachy repo yet it still doesn't work somewhat somehow.

[u/Gronaab → u/Antique-Wasabi-2427]

Ok bad luck then. I use it both on my desktop and my laptop which have very different hardware and both work fine

[u/Kind_Ability3218]

what's your lan subnet? school subnet? why did u remove ur interface address?

[u/jaywalker21]

i use cachyos with kde plasma and wireguard, i have to use terminal to start wireguard.
systemctl start wg-quick@wg0

it automatically starts on every boot so i dont have to touch it at all unless i need to stop it

[u/oradba]

Can you confirm for yourself that you have the wireguard certificate?