JunOS : Setting up DHCP forwarding

By | March 22, 2014

Here is how to configure DHCP forwarding across VLans on JunOS Juniper devices.

set forwarding-options helpers bootp server <DHCP_SERVER_IP>
set forwarding-options helpers bootp interface vlan.<VLAN_ID>

Example : Assuming your DHCP server IP is “192.168.1.1” and the VLans you want DHCP forwarding enabled are “1” and “2” :

set forwarding-options helpers bootp server 192.168.1.1
set forwarding-options helpers bootp interface vlan.1
set forwarding-options helpers bootp interface vlan.2

Then commit the changes.

To see the relay agent statistics, imply do :

show helper statistics

If you run into some issues, these commands will help you to enable the debugging logs :

set forwarding-options helpers traceoptions file helper
set forwarding-options helpers traceoptions flag bootp
set forwarding-options helpers traceoptions level level

Logs will be stored under the following path :

/var/log/helper

Use the following command to show them on screen :

show log helper