Reserves IP addresses for specific hosts. The SecureRamp ensures that only the reserved IP address is assigned to the host that the address is reserved for.
setdhcpreserve -a IP_address -m MAC_address
setdhcpreserve -a 205.15.3.20 -m 001b1a223344
This command will reserve the IP address 205.15.3.20 for the machine that has the MAC address 001b1a223344. The SecureRamp will always assign this IP address to the host with this MAC address, and will never assign this IP address to any host with a different MAC address.