3Com 5500 SI - Switch - Stackable, Configuration Manual

Page: 146 / 686

146 C
HAPTER
10: DHCP S
ERVER
C
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
Troubleshooting DHCP
Server
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.)