When the computer got the *.108 from the old DHCP, it has nothing to do with the ER DHCP. A DHCP server keeps track of its own DHCP range and reserves the IP addresses by MAC address for the configured lease time. New DHCP means new reservation list. Usually the DHCP simply counts up when assigning IPs. If the unreachable computer happens to be the very first device switched on / requesting an IP from the DHCP, it would have received the first IP from the range (e.g. the .100 if the range would be .100 - .199)
Have you checked if one of the DHCP devices actually IS the unreachable computer?
As long as the switch ports are technically ok and you dont use VLANs, it doesn't matter which port you connect the computer. Try another (working) port to be on the safe side.
Have you checked if one of the DHCP devices actually IS the unreachable computer?
As long as the switch ports are technically ok and you dont use VLANs, it doesn't matter which port you connect the computer. Try another (working) port to be on the safe side.