3Com Switch 8800 Configuration Guide Chapter 13 DHCP Configuration
13-17

III. Configuring custom DHCP options for multiple VLAN interfaces

Perform the following configuration in system view.
Table 13-27 Configure custom DHCP options for multiple VLAN interfaces
Operation Command
Configure a custom DHCP option for
DHCP address pools of multiple VLAN
interfaces
dhcp server option code { ascii
ascii-string | hex hex-string | ip-address
ip-address [ ip-address ] } { interface
vlan-interface vlan_id [ to
vlan-interface vlan_id ] | all }
Remove a custom DHCP option
configured for DHCP address pools of
multiple VLAN interfaces
undo dhcp server option code
{ interface vlan-interface vlan_id [ to
vlan-interface vlan_id ] | all }
If you execute the dhcp server option command multiple times, the newly configured
option overwrites the existing one.
13.3.10 Configuring Outbound Gateway Address for DHCP Clients
An outbound gateway enables DHCP clients to access external network devices.
Packets destined for external networks are forwarded by outbound gateways. At
present, you can configure up to eight IP addresses for outbound gateways.
Perform the following configuration in DHCP address pool view.
Table 13-28 Configure outbound gateway address for DHCP clients
Operation Command
Configure one or more outbound
gateway addresses for DHCP clients gateway-list ip-address [ ip-address ]
Remove one or all outbound gateway
addresses configured for DHCP clients undo gateway-list { ip-address | all }
By default, no outbound gateway address is configured for DHCP clients.
If you execute the gateway-list command multiple times, the newly configured IP
addresses overwrite the existing ones.
13.3.11 Configuring Parameters for DHCP Server to Send Ping Packets
To avoid address conflict caused by reassigning an in-use IP address, before assigning
an IP address to a DHCP client, the DHCP server detects the network using the ping
instructions to ensure the IP address is not occupied. The DHCP server determines
whether an IP address is reachable by sending specified number of ping packets. It
waits for response packet for a specified period after sending each of these packets. If