dirtycrow

cross-posted from: https://programming.dev/post/30526871

I needed a PSU that was efficient at 20W and so I consulted Wolfgang's PSU Low Idle Efficiency List, because it was one of the first results on YouTube. However, the first thing you may notice is that the reports it links to are no longer in the same place on Cybenetics' website. If you manually check the PSU model on their website, you actually get different numbers for 20W. After having this revelation, I scraped the entire website and found that Wolfgang's data is no longer current. I don't know why after a second evaluation Cybenetics had different results, but am inviting you to ask with me.

Here are the top 150:

I needed a PSU that was efficient at 20W and so I consulted Wolfgang's PSU Low Idle Efficiency List, because it was one of the first results on YouTube. However, the first thing you may notice is that the reports it links to are no longer in the same place on Cybenetics' website. If you manually check the PSU model on their website, you actually get different numbers for 20W. After having this revelation, I scraped the entire website and found that Wolfgang's data is no longer current. I don't know why after a second evaluation Cybenetics had different results, but am inviting you to ask with me.

Here are the top 150:

They never asked me to make security questions. I set my password the first time and completed some required forms. Then, these buffoons reset my password again (2nd) and made me change it to something else (3rd). The thing is, when I changed my password the site gave me a non-descript error banner and redirected me to the login. Now neither the 1st password, 2nd password, or 3rd password works. To top it off I can't even reset the password. I think the site is having an aneurysm.

Amirite?

If the format seems familiar, it’s because I recently finished “House of Leaves” (no pun intended)

Also, yeah this really happened, which I think makes it funnier. And I eat more fiber nowadays btw.

Could be work or school.

Background: I have a cellular ISP and therefore cannot configure the CGNAT. After burning through some dumb ideas (free reverse proxy, docker) I realized I could just use my paid VPN.

My setup is as follows: on the VPN server create a tunnel to AirVPN and start the openvpn daemon. This creates tun0 and tun1 with their own 10.x.x.x/24 subnets. The home network has 192.168.12.0/24.

It's possible to troubleshoot the MTU with ping -M do -s xxxx y.y.y.y to the VPN public address and test TCP/UDP sockets with nc -l -u -p 1194 .

I'm not sure if the MTU is variable across servers, but for the server I am on now ping -M do -s 1432 x.x.x.x is the biggest I can get a response from. 1432+20+8=1460 bytes.

Regardless, connecting to the home VPN through the AirVPN link still causes breakage. Discord seems to be what isn't working, mostly. Everything else has 200 ms latency as expected and not everything pings correctly. Rarely it will tell me the MTU has to be adjusted, sometimes tells me "message too long" and mostly just ignores my ping.

Can someone give me a recommendation for what MTU to be setting in my local OpenVPN server? Should I use mssfix or tun-mtu? Should I lower the MTU of the AirVPN connection? What else can I do?

Diagram:

Home -> AirVPN <- (1460 MTU) -> OpenVPN Client & server -> (1300 MTU) -> Home -> Outside World

dev tun
proto udp
remote A.B.C.D 34183
tun-mtu 1300
resolv-retry infinite
nobind
user nobody
group nogroup
persist-key
persist-tun
mute-replay-warnings
remote-cert-tls server
key-direction 1
cipher AES-256-CBC
data-ciphers AES-256-CBC
verb 3

proto udp
dev tun
ca /etc/openvpn/easy-rsa/pki/ca.crt
cert /etc/openvpn/easy-rsa/pki/issued/server.crt
key /etc/openvpn/easy-rsa/pki/private/server.key
dh /etc/openvpn/easy-rsa/pki/dh.pem
topology subnet
tun-mtu 1300
server 10.9.8.0 255.255.255.0
ifconfig-pool-persist ipp.txt
push "route 192.168.12.0 255.255.255.0"
push "redirect-gateway def1 bypass-dhcp"
push "dhcp-option DNS 1.1.1.1"
keepalive 10 120
tls-server
tls-auth /etc/openvpn/server/ta.key 0
auth-nocache
user nobody
group nogroup
cipher AES-256-CBC
data-ciphers AES-256-CBC
status /var/log/openvpn/openvpn-status.log
persist-tun
persist-key
verb 3
client-to-client
explicit-exit-notify 1

dev tun
remote [spoiler].vpn.airdns.org 443
resolv-retry infinite
nobind
tun-mtu 1460
persist-key
persist-tun
auth-nocache
verb 3
explicit-exit-notify 5
push-peer-info
setenv UV_IPV6 yes
remote-cert-tls server
comp-lzo no
data-ciphers AES-256-GCM:AES-256-CBC:AES-192-GCM:AES-192-CBC:AES-128-GCM:AES-128-CBC
data-ciphers-fallback AES-256-CBC
proto udp
auth SHA512

In the process of doing this I somehow shut my house's WiFi down...