MikroTik RouterOS v2.9 Reference Manual page 501

DHCP server lease submenu is used to monitor and manage server's leases. The issued leases are
showed here as dynamic entries. You can also add static leases to issue the definite client
(determined by MAC address) the specified IP address.
Generally, the DHCP lease it allocated as follows:
1. an unused lease is in waiting state
2. if a client asks for an IP address, the server chooses one
3. if the client will receive statically assigned address, the lease becomes offered, and then
bound with the respective lease time
4. if the client will receive a dynamic address (taken from an IP address pool), the router sends a
ping packet and waits for answer for 0.5 seconds. During this time, the lease is marked testing
5. in case, the address does not respond, the lease becomes offered, and then bound with the
respective lease time
6. in other case, the lease becomes busy for the lease time (there is a command to retest all busy
addresses), and the client's request remains unanswered (the client will try again shortly)
A client may free the leased address. When the dynamic lease is removed, and the allocated address
is returned to the address pool. But the static lease becomes busy until the client will reacquire the
address.
Note that the IP addresses assigned statically are not probed.
Property Description
active-address ( read-only: IP address ) - actual IP address for this lease
active-client-id ( read-only: text ) - actual client-id of the client
active-mac-address ( read-only: MAC address ) - actual MAC address of the client
active-server ( read-only: ) - actual dhcp server, which serves this client
address ( IP address ) - specify ip address (or ip pool) for static lease
• 0.0.0.0 - use pool from server
agent-circuit-id ( read-only: text ) - circuit ID of DHCP relay agent
agent-remote-id ( read-only: text ) - Remote ID, set by DHCP relay agent
block-access ( yes | no ; default: no ) - block access for this client (drop packets from this client)
client-id ( text ; default: "" ) - if specified, must match DHCP 'client identifier' option of the
request
expires-after ( read-only: time ) - time until lease expires
host-name ( read-only: text ) - shows host name option from last received DHCP request
lease-time ( time ; default: 0s ) - time that the client may use an address
• 0s - lease will never expire
mac-address ( MAC address ; default: 00:00:00:00:00:00 ) - if specified, must match MAC
address of the client
radius ( read-only: yes | no ) - shows, whether this dynamic lease is authenticated by RADIUS or
not
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