Dell PowerConnect J-EX4200-24T Software Manual page 2688

Dell PowerConnect J-Series Ethernet Switch Complete Software Guide for Junos OS
Configuration
CLI Quick
Configuration
Step-by-Step
Procedure
2616
of that request. The switch then sends the request (in this setting, it relays the request)
to the DHCP server. The DHCP server reads the option 82 information in the packet header
and uses it to implement the IP address or other parameter for the client.
When option 82 is enabled on the switch, then this sequence of events occurs when a
DHCP client sends a DHCP request:
The switch receives the request and inserts the option 82 information in the packet
1.
header.
The switch relays the request to the DHCP server.
2.
The server uses the DHCP option 82 information to formulate its reply and sends a
3.
response back to the switch. It does not alter the option 82 information.
The switch strips the option 82 information from the response packet.
4.
The switch forwards the response packet to the client.
5.
In this example, you configure option 82 on the J-EX Series switch. The switch is configured
as a BOOTP relay agent. The switch connects to the DHCP server through the routed
VLAN interface (RVI) that you configured. The switch and clients are members of the
VLAN. The DHCP server is a member of the
employee
To configure DHCP option 82:
To quickly configure DHCP option 82, copy the following commands and paste them
into the switch terminal window:
set forwarding-options helpers bootp dhcp-option82
set forwarding-options helpers bootp dhcp-option82 circuit-id prefix hostname
set forwarding-options helpers bootp dhcp-option82 circuit-id use-vlan-id
set forwarding-options helpers bootp dhcp-option82 remote-id
set forwarding-options helpers bootp dhcp-option82 remote-id prefix mac
set forwarding-options helpers bootp dhcp-option82 remote-id use-string employee-switch1
set forwarding-options helpers bootp dhcp-option82 vendor-id
To configure DHCP option 82:
Specify DHCP option 82 for the
1.
[edit forwarding-options helpers bootp]
user@switch# set dhcp-option82
Configure a prefix for the circuit ID suboption (the prefix is always the hostname of
2.
the switch):
[edit forwarding-options helpers bootp]
user@switch# set dhcp-option82 circuit-id prefix hostname
Specify that the circuit ID suboption value contains the VLAN ID rather than the
3.
VLAN name (the default):
[edit forwarding-options helpers bootp]
user@switch# set dhcp-option82 circuit-id use-vlan-id
Specify that the remote ID suboption be included in the DHCP option 82 information:
4.
corporate
employee VLAN:
VLAN.