Showing DHCP Status

Problem

You want to display the status of the DHCP server functions on the router.

Solution

To display the IP address bindings and their associated leases, use the following command:

Router1#show ip dhcp binding

The following command displays any IP address conflicts that the router has detected in the DHCP address pool:

Router1#show ip dhcp conflict

You can view the status of remote database backups with this command:

Router1#show ip dhcp database

And you can see the global DHCP server statistics like this:

Router1#show ip dhcp server statistics

Discussion

To display the status of the DHCP service, use the show ip dhcp EXEC command. If you add the keyword binding, this command displays the current DHCP bindings, which include the assigned IP addresses, the associated client MAC addresses, and the lease expiration time:

Router1#show ip dhcp binding
IP address       Hardware address        Lease expiration        Type
172.25.1.51      0100.0103.85e9.87       Apr 10 2006 08:55 PM    Automatic
172.25.1.52      0100.50da.2a5e.a2       Apr 10 2006 09:00 PM    Automatic
172.25.1.53      0100.0103.ea1b.ed       Apr 10 2006 08:58 PM    Automatic
Router1#

To view the IP addresses that are currently in conflict, use the conflict keyword. This command displays all of the IP addresses that the router has discovered conflicts for, and how the conflict was discovered:

Router1#show ip dhcp conflict 
IP address        Detection method   Detection time
172.25.1.51       Ping               Apr 09 2006 09:08 PM
172.25.1.54       Gratuitous ARP     Apr 09 2006 10:00 PM
Router1#

With the database keyword, you can view the database configuration and status. This command shows all of the configured remote database servers and the current read and write status reports:

Router1#show ip dhcp database 
URL      : ftp://dhcp:bindsave@172.25.1.1/dhcp-leases
Read     : Never
Written  : Apr 09 2006 10:24 PM
Status   : Last write succeeded. Agent information is up-to-date.
Delay    : 300 seconds
Timeout  : 300 seconds
Failures : 1
Successes: 30

Router1#

Finally, the statistics keyword lets you view the overall DHCP statistics:

Router1#show ip dhcp server statistics 
Memory usage         17996
Address pools        4
Database agents      1
Automatic bindings   2
Manual bindings      1
Expired bindings     3
Malformed messages   0

Message              Received
BOOTREQUEST          0
DHCPDISCOVER         63
DHCPREQUEST          203
DHCPDECLINE          1
DHCPRELEASE          27
DHCPINFORM           19

Message              Sent
BOOTREPLY            0
DHCPOFFER            63
DHCPACK              139
DHCPNAK              2
Router1#

This command displays the high-level DHCP statistics, including the number of bindings, address pools, as well as the number of sent and received messages.

Showing DHCP Status