Distillation

Date: Sep 17, 2026

• 🟡 (08:51) ethtool version 1:6.7-1build1 was installed from Ubuntu Noble (http://gb.archive.ubuntu.com/ubuntu noble/main amd64); sudo could not elevate because the "no new privileges" flag was set, with the diagnostic suggesting container configuration may need adjustment.
• 🟡 (08:51) Offload inspection showed active interfaces br0 and enp2s0. On br0, rx-udp-gro-forwarding: off and rx-gro-list: off; generic-receive-offload: on, while scatter-gather, tcp-segmentation-offload, and generic-segmentation-offload were off despite being requested on. On enp2s0, rx-udp-gro-forwarding: off, rx-gro-list: off, and generic-receive-offload: on.
• 🟡 (08:51) /etc/networkd-dispatcher/routable.d contained exactly 1 entry: 50-tailscale.
• 🟡 (08:52) Existing persistence script /etc/networkd-dispatcher/routable.d/50-tailscale was a 3-line executable shell script whose command was ethtool -K enp1s0 rx-udp-gro-forwarding on rx-gro-list off.
• 🟡 (08:52) Tailscale network-performance issue root cause was confirmed: /etc/networkd-dispatcher/routable.d/50-tailscale targeted obsolete/nonexistent interface enp1s0, while default traffic now routes through br0; therefore rx-udp-gro-forwarding remained disabled on br0. The required rx-gro-list setting was already off.
• 🟡 (08:52) Assistant staged a corrected idempotent persistence script as tmp/opencode/50-tailscale for privileged installation, with the intended source path referenced as /tmp/opencode/50-tailscale.
• 🟡 (08:52) Assistant instructed the user to install and execute the corrected script using, in order: 1. sudo install -m 0755 /tmp/opencode/50-tailscale /etc/networkd-dispatcher/routable.d/50-tailscale; 2. sudo /etc/networkd-dispatcher/routable.d/50-tailscale.
• 🟡 (08:52) Assistant planned follow-up verification of the offload flags, Tailscale health, and reboot persistence after the user reported the command result.