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Monitoring DHCP Services



This topic applies only to the J-Web Application package.

A switch or router can operate as a DHCP server. Use the monitoring functionality to view information about dynamic and static DHCP leases, conflicts, pools, and statistics.


To monitor the DHCP server in the J-Web interface, select Monitor > Services > DHCP.

To monitor the DHCP server in the CLI, enter the following CLI commands:

  • show system services dhcp binding

  • show system services dhcp conflict

  • show system services dhcp pool

  • show system services dhcp statistics

  • show system services dhcp relay-statistics

  • show system services dhcp global

  • show system services dhcp client

  • clear system services dhcp binding

  • clear system services dhcp conflict

  • clear system services dhcp statistics

  • clear dhcp relay-statistics


Table 1 summarizes the output fields in DHCP displays in the J-Web interface.

Table 1: Summary of DHCP Output Fields



Additional Information

Global tab


This column displays the following information:

  • Boot lease length

  • Domain Name

  • Name servers

  • Server identifier

  • Domain search

  • Gateway routers

  • WINS server

  • Boot file

  • Boot server

  • Default lease time

  • Minimum lease time

  • Maximum lease time



Displays the value for each of the parameters in the Name column.

Bindings tab

Allocated Address

List of IP addresses the DHCP server has assigned to clients.


MAC Address

Corresponding media access control (MAC) address of the client.


Binding Type

Type of binding assigned to the client: dynamic or static.

DHCP servers can assign a dynamic binding from a pool of IP addresses or a static binding to one or more specific IP addresses.

Lease Expires

Date and time the lease expires, or never for leases that do not expire.

Pools tab

Pool Name

Subnet on which the IP address pool is defined.


Low Address

Lowest address in the IP address pool.


High Address

Highest address in the IP address pool.


Excluded Addresses

Addresses excluded from the address pool.

Clients tab

Interface Name

Name of the logical interface.


Hardware Address

Vendor identification.



State of the client binding.


Address Obtained

IP address obtained from the DHCP server.


Update Server

Indicates whether server update is enabled.


Lease Obtained

Date and time the lease was obtained.


Lease Expires

Date and time the lease expires.



Reacquires an IP address from the server for the interface. When you click this option, the command sends a discover message if the client state is INIT and a renew request message if the client state is BOUND. For all other states it performs no action.



Clears other resources received earlier from the server, and reinitializes the client state to INIT for the particular interface.

Conflicts tab

Detection Time

Date and time the client detected the conflict.


Detection Method

How the conflict was detected.

Only client-detected conflicts are displayed.


IP address where the conflict occurs.

The addresses in the conflicts list remain excluded until you use the clear system services dhcp conflict command to manually clear the list.

DHCP Statistics
Relay Statistics tab

Packet Counters

Displays the number of packet counters.


Dropped Packet Counters

Graphically displays the number of dropped packet counters.

Statistics tab

Packets dropped

Total number of packets dropped and the number of packets dropped due to a particular condition.


Messages received

Number of BOOTREQUEST, DHCPDECLINE, DHCPDISCOVER, DHCPINFORM, DHCPRELEASE, and DHCPREQUEST messages sent from DHCP clients and received by the DHCP server.


Messages sent

Number of BOOTREPLY, DHCPACK, DHCPOFFER, DHCPNAK, and DHCPFORCERENEW messages sent from the DHCP server to DHCP clients.