I would like to know, if there is a way I could force the DHCP server to renew the IP address of a client machine instantly, without me going to the client machine? In fact, imagine, I don't have access to the client machine.
So, here is my scenario,
The client first gets a Random IP address say A from the DHCP server initially, when it is connected to the LAN. Imagine, someone connected the client to the LAN and he didn't map any IP address to its MAC address in the dhcpd.conf to begin with.
I would like to mention here that, there are other machines in the same subnet that already have IP address to MAC address mapping configured in the dhcpd.conf.
Next, I modify the dhcpd.conf file to map a new IP address B for the client to its MAC address.
But, now I need the old IP address A to be changed instantly to B.
I don't want to tweak default-lease-time or mess around with the lease time in dhcpd.conf.
Any other ways like restarting the services are fine since, excluding that one machine, all others already have their IP addresses tied to the MAC addresses in the dhcpd.conf.
Note: I cannot reboot any machines in the LAN, not even the machine which is running the dhcp server.
Hope I made myself quite clear.