DHCP Leases And Cleanup

[lewty1987]

Hey all,
I am having issues with the route10 and its ability to clean up leases in DHCP. Currently, my site is showing 149 devices… Which is highly inaccurate (120 are inactive). I just went through and cleaned up about 50 of them. Reloaded the page… and they all came back.

What is happening with this? There is no mass delete of disconnected/offline leases. My Lease time is set for the default 1 day.

What can I do?

[jmszuch]

Before you do what I’m about to suggest, I might recommend doing a screen recording of that reloading behavior and kicking off a support request to make sure that gets looked at further: https://help.alta.inc/hc/en-us/requests/new

But anyway! Should be able to clear out the DHCP leases from the terminal since I don’t believe that’s been implimented yet in the controller. Should be something like the following:

• Shift+click on the router name in the controller to open the terminal
• If we want to remove all the DHCP leases (for the sake of simplicity), this command should do it rm /cfg/dhcp.leases
• Could also manually edit that file with nano /cfg/dhcp.leases
• Then the dnsmasq service needs to be restarted /etc/init.d/dnsmasq restart or the router as a whole could be rebooted

If it’s excess DHCP leases causing the issue then that should hopefully clear them out.

I might also suggest lowering the DHCP lease time to something like 8 hours (28800). Or even lower if it’s a network where lots of devices come in and out. I’ve often found Apple recommendations for their client devices pretty decent in this regard: Recommended settings for Wi-Fi routers and access points - Apple Support

Hope that helps!

[lewty1987]

Might have been a fluke… I stepped away form it and came back a few days later (I did lower my DHCP lease time from the default) and its showing the correct device count + allows me to remove old VM’s now.