DESCRIPTION

Every allocation made by the DHCP server built-in to the FB2500 is stored in non-volatile memory, and as such will survive power-cycling and/or rebooting. The allocations can be seen using this command. If an IP address is specified, then details of the allocation for that address will be shown, otherwise all allocation information will be shown.

If a client does not request renewal of the lease before it expires, the allocation entry will show "expired". Expired entries remain stored, and are used to lease the same IP address again if the same client requests an address. However, if a new MAC address requests an allocation, there are no available IPs (excluding expired allocations) in an allocation pool, then the oldest expired allocation IP address is re-used for the new client.

You can clear expired, or any other entries, using the clear dhcp command - you may need to do this if you setup a static MAC-address-based DHCP allocation for a client, but it has already obtained an address from a pool ; by clearing the allocation, then getting the client to issue another DHCP request, it should pick up the new static allocation. If you do not clear the allocation, then the client will obtain the same address it did before you set up the MAC-based static allocation.

EXAMPLE

marty> sh dhcp
DHCP
----
T Interface                MAC      IP address Client name                    
0 LAN        00:90:f5:9e:4f:12    81.187.96.81 enceladus                    
0 LAN        7c:2f:80:17:0a:5c    81.187.96.83 N300-IP               

      

The "Interface" column shows which interface (i.e. broadcast domain) was involved in the DHCP request/reply process.

The "Client name" column will typically show the client host-name, or perhaps a product name (as in the example above, where "N300-IP" is a VoIP DECT basestation).