3com 8807 User Guide

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C
HAPTER
 57: DHCP C
ONFIGURATION
Network diagram
Figure 166   Network diagram for Option 82 support on DHCP relay configuration
Configuration procedure
Suppose the DHCP relay and the DHCP server is reachable to each other. The 
following only introduces the configuration on the switch which serves as the 
DHCP relay.
# Enable the DHCP service
<SW8800> system-view
 
[SW8800] dhcp enable 
# Enter the view of the interface on which the DHCP relay function will be 
enabled. Configure an IP address and a subnet mask for the interface so that it 
belongs to the same network segment with the DHCP client
[SW8800] interface vlan-interface 100
 
[3Com-vlan-interface 100] ip address 10.110.1.1 255.255.0.0 
# Enable the DHCP relay function on the interface, and configure an IP address for 
the DHCP relay function (this address specifies the location of the DHCP server for 
this interface). Enable Option 82 support on DHCP relay and specify the strategy 
to keep. Specify the mode as 3Com fixed network mode and the system name as 
the node identifier.
[SW8800] interface vlan-interface 100
 
[3Com-vlan-interface 100 ] dhcp select relay
 
[3Com-vlan-interface 100] ip relay address 202.38.1.2
 
[3Com-vlan-interface 100] dhcp relay information enable
 
[3Com-vlan-interface 100] dhcp relay information strategy keep
 
[3Com-vlan-interface 100] dhcp relay information format verbose
 
[3Com-vlan-interface 100] dhcp relay information format verbose node-
 
identifier sysname 
The configuration of the DHCP server is omitted here.
Ethernet
Ethernet
Interne
t
DHCP client
DHCP client
Switch ( DHCP relay )
10.110.0.0
DHCP server
202.38.1.2
10.110.1.1
202.38.0.0
202.38.1.1
Ethernet
Ethernet
Interne
t
DHCP client
DHCP client
10.110.0.0
202.38.1.2
10.110.1.1
202.38.0.0
202.38.1.1
Ethernet
Ethernet
Interne
t
DHCP client
DHCP client
Switch ( DHCP relay )
10.110.0.0
DHCP server
202.38.1.2
10.110.1.1
202.38.0.0
202.38.1.1
Ethernet
Ethernet
Interne
t
DHCP client
DHCP client
10.110.0.0
202.38.1.2
10.110.1.1
202.38.0.0
202.38.1.1
Ethernet
Ethernet
Interne
t
DHCP client
DHCP client
Switch ( DHCP relay )
10.110.0.0
DHCP server
202.38.1.2
10.110.1.1
202.38.0.0
202.38.1.1
Ethernet
Ethernet
Interne
t
DHCP client
DHCP client
10.110.0.0
202.38.1.2
10.110.1.1
202.38.0.0
202.38.1.1