Problem: when your programs try to resolve a name, glibc caches the contents of /etc/resolv.conf, which may be still empty by the time when /etc/rc.local is run. Wget process is restarted and has a chance to read a valid /etc/resolv.conf with nameservers inside, while your Perl script just runs and doesn't know that resolv.conf was overwritten with valid nameservers.

Solutions:

  1. (proper) Write a proper unit file for your scripts, so they start after NetworkManager has a working connection to the internet.
  2. Discard NM and use a static resolv.conf which does not change between reboots.
  3. (improper solutions start here) Add some sleep in your rc.local before launching your scripts.
  4. Move sleep 180 to the beginning of the loop, so the first gethostbyname will have a chance to wait for the connection to appear before caching resolv.conf.

In reply to Re: Systemd Network Problem by Anonymous Monk
in thread Systemd Network Problem by Anonymous Monk

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