Raspberry Pi + Tailscale exit node: UDP GRO config

udpgroforwarding.service

[Unit] 
Description= UDPGroForwarding 
Wants=network-online.target 
After=network-online.target

[Service] 
Type=oneshot 
ExecStart=/sbin/ethtool -K eth0 rx-udp-gro-forwarding on rx-gro-list off

[Install] 
WantedBy=multi-user.target

Raspberry Pi + Tailscale exit node: UDP GRO config

This is the systemd service you can add to fix the UDP GRO config warning when turning a Tailscale node as an exit node in a Raspberry Pi.

Place it inside the /etc/systemd/system directory, then reload daemons, enable it and start it.

Ensure eth0 is your interface. You can use the following command to know:

ip -o route get 8.8.8.8 | cut -f 5 -d " "

Commands:

curl https://gist.githubusercontent.com/davidlj95/d099d722848f041d89d65dba891e7031/raw | sudo tee -a /etc/systemd/system/udpgroforwarding.service
sudo systemctl daemon-reload
sudo systemctl start udpgroforwarding.service
sudo systemctl enable udpgroforwarding.service # so it's applied after reboot

Check if the config was applied successfully by using the following command:

ethtool -k eth0 | grep gro-list
ethtool -k eth0 | grep forwarding

Also if running sudo tailscale up --advertise-exit-node no warning should appear this time.

Source:
https://www.reddit.com/r/Tailscale/comments/18qzf9f/comment/kf0sha4/