Troubleshooting Dhcp Server - 3Com 5500-SI Configuration Manual

146 C 10: DHCP S
HAPTER
Troubleshooting DHCP
Server
C
ERVER ONFIGURATION
5 Return to system view.
[S5500-dhcp-pool-1] quit
6 Configure DHCP address pool 2, including address range, domain name, DNS server
address, lease time, NetBIOS server address, and gateway address.
[S5500] dhcp server ip-pool 2
[S5500-dhcp-pool-2] network 10.1.1.128 mask 255.255.255.128
[S5500-dhcp-pool-2] domain-name aabbcc.com
[S5500-dhcp-pool-2] dns-list 10.1.1.2
[S5500-dhcp-pool-2] expired day 5
[S5500-dhcp-pool-2] nbns-list 10.1.1.4
[S5500-dhcp-pool-2] gateway-list 10.1.1.254
Symptom
The IP address dynamically assigned by a DHCP server to a client conflicts with the IP
address of another host.
Analysis
With DHCP enabled, IP address conflicts are usually caused by IP addresses that are
manually configured on hosts.
Solution
Disconnect the DHCP client from the network and then check whether there is a
■
host using the conflicting IP address by performing ping operation on another host
on the network, with the conflicting IP address as the destination and an enough
timeout time.
The IP address is manually configured on a host if you receive a response packet of
■
the ping operation. You can then disable the IP address from being dynamically
assigned by using the dhcp server forbidden-ip command.
Attach the DHCP client to the network, release the dynamically assigned IP address
■
and apply an IP address again. (You can release a dynamically assigned IP address
by executing the winipcfg command in Windows 98 or by executing the
ipconfig/release command in Windows 2000/XP. You can refresh the IP address by
using the ipconfig/release_all and ipconfig/renew_all commands in DOS.)