jetson-pc-wired-share

Jetson PC wired internet sharing

Use a separate, non-autoconnecting NetworkManager profile on the PC. Keep the original wired profile intact so the operation is easy to reverse. Never put a sudo or SSH password in this skill, a connection profile, a script, or a log.

Start sharing

1. Inspect before changing anything:

   • nmcli device status, active connections, ip -br addr, and ip route.
   • ip route get <jetson-ip> to identify the PC interface carrying SSH.
   • The Jetson's interface, address, routes, and DNS over the existing SSH link.
   • Confirm the PC has a working upstream/default route on a different interface.

2. Determine the downstream PC address:

   • If the Jetson already has a static address and SSH uses the wired subnet, preserve the PC's existing address and subnet. This avoids losing SSH.
   • Otherwise choose an unused RFC1918 /24 that does not overlap any PC or Jetson route; NetworkManager's usual 10.42.0.1/24 is acceptable only after checking for conflicts.

3. Create or update a profile named jetson-wired-share on the downstream interface. Set connection.autoconnect no, ipv4.method shared, the chosen ipv4.addresses, ipv4.never-default yes, and ipv6.method disabled. Then activate it. Do not edit or delete the original wired profile. Example shape:

   sudo nmcli connection add type ethernet \
     ifname <pc-wired-interface> con-name jetson-wired-share autoconnect no \
     ipv4.method shared ipv4.addresses <pc-address/cidr> \
     ipv4.never-default yes ipv6.method disabled
   sudo nmcli connection up jetson-wired-share
   

   If that profile already exists, use nmcli connection modify instead of creating a duplicate. Warn that activation may briefly flap the wired link.

4. Configure the Jetson without making its static profile persistent unless the user explicitly asks. For an already-static Jetson, add a runtime route:

   sudo ip route replace default via <pc-wired-ip> dev <jetson-interface> metric 100