Summary

I have a old laptop that’s serving me as a Technitium DNS server and Tailscale exit node.

My setup is behind a CGNAT, but the Tailscale make its way around and that’s not an issue. My VPN exit node works flawlessly.

However I also set my router to make my laptop as DNS server, so all my lan network is passing through the Technitium. So, in theory all my local network is using my selfhosted DNS server.

Issue

The issue here is not the server itself, cause it’s working as intended - when I can connect to it.

What’s going on is that my server for once in a while become unreachable from lan. If I try to ping it from another device in local network, it returns that it’s unreachable, but my server still connected to the internet (I can ping Google, for example). So to solve it, I must do one of the below:

  • Kick the server from the router, forcing it to reconnect
  • Connect to the Tailscale VPN and ping it from the Tailscale ip
  • Reboot my server

It anoys me because it’s not supposed to the server become unreachable in local randomly!

It’s important to comment that the server isn’t connected through ethernet, but it uses wifi because I can’t put my laptop near the router. The laptop is close enough to not have any wifi interference, however.

What can I do to prevent my server to become unreachable?

My setup

Server

  • An old Acer laptop connected to the wifi
  • Static IP configured
  • SO: Arch Linux (as server, no GUI at all)

Router

D-Link DIR-842

Thank you in advance

  • hayalci@fstab.shEnglish
    2·
    1 year ago

    Random idea, continuously ping the router from the laptop so it doesn’t “forget” that the laptop exists on the WLAN?

    (I know you mention the laptop can still reach out when you try, but maybe the trick is to keep having traffic to-from the laptop continuously)

    • BaalInvokerOPAEnglish
      11·
      1 year ago

      Well, I may try this… Maybe set a systemd timer to ping the router for once in a while…

      But I’ll wait to check if disabling saving mode do the job. If it doens’t I’ll try the ping workaround