Dropp lease for IP

[PcGuy]

Is there still no way of dropping a lease for a DHCP assigned IP address so that that fixed IP address configured via MACID can be assigned for that particular device?

 

[ColinTaylor]

A DHCP server can't "drop a lease" that it's already given to a client.

If you want to reassign an IP address to a different client then power off the DHCP client that currently has that address, make your change on the DHCP server, and then turn the old client back on. The DHCP server will refuse to give the old client its previous address and it will be forced to use a different address.

 

[PcGuy]

I have a device it has gotten assigned an IP address via the DHCP. I have hard coded an IP address for that device via its MACID in the Merlin firmware. Powering off the device letting it sit for several minutes results in it still having the DHCP address assigned to it rather than the hard coded IP address based on its MACID.

 

[ColinTaylor]

I have a device it has gotten assigned an IP address via the DHCP. I have hard coded an IP address for that device via its MACID in the Merlin firmware. Powering off the device letting it sit for several minutes results in it still having the DHCP address assigned to it rather than the hard coded IP address based on its MACID.

By "hard coded" I assume you mean a reservation in DHCP. If so it should have picked up the new address when the client was power-cycled.

Make sure the client isn't connected to the guest wireless network.

What is this device? Is it wired or wireless?

If you look in the router's System Log you should be able to see the DHCP messages when the client connects.

The quickest solution might be to simply reboot the router.

 

[PcGuy]

The devices are Raspberry PI devices. Wired connection only. Yes rebooting the router forces the reservation address to take effect but thought there must be a way to not cause everyone else connected to the router to lose their network connections

 

[ColinTaylor]

The devices are Raspberry PI devices. Wired connection only. Yes rebooting the router forces the reservation address to take effect but thought there must be a way to not cause everyone else connected to the router to lose their network connections

I can't think why the Raspberry Pis would be different from any other client. Simply unplugging and reconnecting its ethernet cable should have had the same effect.

I've just tried changing the IP of one of my DHCP clients and it worked as expected. I've done this many times in the past.

Maybe it's a bug in the particular firmware version you're using. The System Log should show you what's happening when the client connects.

P.S. When you apply the changes to the DHCP reservations you should see dnsmasq being restated in the System Log.

 

[drinkingbird]

The devices are Raspberry PI devices. Wired connection only. Yes rebooting the router forces the reservation address to take effect but thought there must be a way to not cause everyone else connected to the router to lose their network connections

Yeah sounds like a bug of some sort - as @ColinTaylor says a release/renew or even just plain renew (which happens when you unplug/plug the ethernet) will get it the reserved IP, have seen this work fine on mine many times. Client says "I want this IP", server says "not available, take this one". Unless the RPis are misbehaving somehow, potentially blocking TCP DHCP and only allowing UDP which can cause some oddities. Or they're just flat out ignoring the response. But in that case rebooting the Pi should work. or even doing a release then renew of DHCP on them.

 

[PcGuy]

I had some time to do further testing. I changed the reserved IP address for one of these devices and applied the settings which got this in the logs:

May 20 11:12:04 rc_service: httpd 1401:notify_rc restart_dnsmasq
May 20 11:12:05 dnsmasq-dhcp[5748]: not giving name RaspPi4_2GB to the DHCP lease of 192.168.1.11 because the name exists in /etc/hosts with address 192.168.1.13

Then I unplugged the network cable and the device got its .13 address like it should. No idea what was going on the other day.

 

[ColinTaylor]

Then I unplugged the network cable and the device got its .13 address like it should. No idea what was going on the other day.

You're not using Wi-Fi and Ethernet on the Pi at the same time are you?

 

[PcGuy]

Nope only wired