Cont. Clear all DHCP leases

[anowak]

This is in regards to discussion.

Clear all DHCP leases

Hi All, This question has been asked before but never really answered or I’ve miss read it. I want a simple way to just flush all DHCP lease entries. I am running VyOS 1.4 There is a command: clear dhcp-server lease Although if I have 50+ leases I don’t want to be going through them individually. So I thought something like this may work show dhcp server leases | awk "{print $1}" | xargs -I {} clear dhcp-server lease {} Unfortunately this failed Maybe because the script tem…

tjh: I tried your recommendation, but get similar result.

show dhcp server leases | grep 'free' | awk 'NR >2 {print $1}' | xargs -I {} clear dhcp-server lease {}
Usage: clear [options]

Options:
  -T TERM     use this instead of $TERM
  -V          print curses-version
  -x          do not try to clear scrollback
Usage: clear [options]

Options:
  -T TERM     use this instead of $TERM
  -V          print curses-version
  -x          do not try to clear scrollback
Usage: clear [options]
..
..
..

Is there a way to run xargs -I {} under vyos?

[anowak]

I may have found a way just to get rid of the free leases

Each time you run clear dhcp lease $IP it asks

This will restart DHCP server.
Continue? [y/N]

So came up with script below which grabs only the “free” leases and loops through removing each one, one at a time. Need to sleep long enough to restart the dhcp service. Tried using yes n | for no, but that did not continue with deletion.

show dhcp server lease | grep "free" | awk '{print $1}' | while read ip; do
  yes | clear dhcp lease $ip
  sleep 5  # Sleep for 5 seconds after clearing each lease
done

Seems to work …