Troubleshooting A Dhcp Server - 3Com 7757 Configuration Manual

Troubleshooting a
DHCP Server
Configuration procedure
1 Configure a VLAN and add a port in this VLAN, and then configure the IP address
of the VLAN interface (omitted).
2 Configure DHCP service.
# Enable DHCP.
<SW7750> system-view
[SW7750] dhcp enable
# Configure the IP addresses that are not dynamically assigned. (That is, the IP
addresses of the DNS server, WINS server, and gateways.)
[SW7750] dhcp server forbidden-ip 10.1.1.2
[SW7750] dhcp server forbidden-ip 10.1.1.4
[SW7750] dhcp server forbidden-ip 10.1.1.126
[SW7750] dhcp server forbidden-ip 10.1.1.254
# Configure DHCP address pool 0, including address range and DNS server
address.
[SW7750] dhcp server ip-pool 0
[SW7750-dhcp-pool-0] network 10.1.1.0 mask 255.255.255.0
[SW7750-dhcp-pool-0] domain-name aabbcc.com
[SW7750-dhcp-pool-0] dns-list 10.1.1.2
[SW7750-dhcp-pool-0] quit
# Configure DHCP address pool 1, including address range, gateway, and lease
time.
[SW7750] dhcp server ip-pool 1
[SW7750-dhcp-pool-1] network 10.1.1.0 mask 255.255.255.128
[SW7750-dhcp-pool-1] gateway-list 10.1.1.126
[SW7750-dhcp-pool-1] expired day 10 hour 12
[SW7750-dhcp-pool-1] quit
# Configure DHCP address pool 2, including address range, gateway, WINS server
address, and lease time.
[SW7750] dhcp server ip-pool 2
[SW7750-dhcp-pool-2] network 10.1.1.128 mask 255.255.255.128
[SW7750-dhcp-pool-2] expired day 5
[SW7750-dhcp-pool-2] nbns-list 10.1.1.4
[SW7750-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.

Troubleshooting a DHCP Server

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