Viktor Jaep
Part of the Furniture
@bukso, your OpenVPN parameters had me question some of my settings, so I dove into it deeper. Please keep in mind, I'm definitely no expert here. When I look at the expressvpn.com site on instructions for configuring OpenVPN on an Asus router using Merlin's firmware (https://www.expressvpn.com/support/vpn-setup/manual-config-for-asus-router-with-openvpn/), they give you this sample config to use... and looks just like yours:OpenVPN advanced parameters I use are copied from ExpressVPN website and are meant for Merlin firmware:
fast-io
remote-random
pull
tls-client
verify-x509-name Server name-prefix
ns-cert-type server
route-method exe
route-delay 2
tun-mtu 1500
fragment 1300
mssfix 1200
keysize 256
sndbuf 524288
rcvbuf 524288
fast-io
remote-random
pull
tls-client
verify-x509-name Server name-prefix
ns-cert-type server
route-method exe
route-delay 2
tun-mtu 1500
fragment 1300
mssfix 1200
keysize 256
sndbuf 524288
rcvbuf 524288
... but in my own config, my mssfix was set to 1450, and things seemed to be working fine, and wanted to understand the difference. So I looked up how to properly configure mtu and mssfix using these instructions: https://www.sonassi.com/help/troubleshooting/setting-correct-mtu-for-openvpn
So I found out that using this method: ping -n 1 -l 1500 -f www.example.com -- that my MTU was actually 1470... and subtracting 40 from that would make my mssfix 1430.
I applied these settings hoping to see some kind of difference, but I didn't see any increase or decrease in speed, plus I started seeing a tun-mtu warning now in the logs... I'm not sure what to do about the link-mtu since I don't specify it anywhere, but I guess that's normal.
Feb 10 06:00:01 ovpn-client1[15002]: WARNING: 'link-mtu' is used inconsistently, local='link-mtu 1560', remote='link-mtu 1606'
Feb 10 06:00:01 ovpn-client1[15002]: WARNING: 'tun-mtu' is used inconsistently, local='tun-mtu 1470', remote='tun-mtu 1500'
So I changed my tun-mtu back to 1500, and am using mssfix 1460... so far so good. Speedtests are still the same... I'm sure this wasn't much help, but it was a good exercise.