You can configure the Juniper Networks EX Series switch to act as a Dynamic Host Configuration Protocol (DHCP) or Bootstrap Protocol (BOOTP) relay agent. This means that a locally attached host can issue a DHCP or BOOTP request as a broadcast message. If the EX Switch sees this broadcast message, it relays the message to a specified DHCP or BOOTP server. To configure an EX Series switch with support for ELS, refer to  Configuring a DHCP Relay Agent on EX Series Switches .

This article details the steps to configure a legacy EX-series switch to act as a DHCP/BOOTP relay agent.

You can configure the router or an interface to act as a Dynamic Host Configuration Protocol (DHCP) or Bootstrap Protocol (BOOTP) relay agent. This means that a locally attached host can issue a DHCP or BOOTP request as a broadcast message. If the switch or an interface sees this broadcast message, it relays the message to a specified DHCP or BOOTP server.

You should configure the interface to be a DHCP/BOOTP relay agent if you have locally attached hosts and a distant DHCP or BOOTP server. To configure the router to act as a DHCP/BOOTP relay agent, include the bootp statement at the [edit forwarding-options helpers] hierarchy level.

The following step is used to configure the EX-Series switch as a DHCP Relay Agent.

1. To specify the IP address of the DHCP server and the interface on the switch where the server is connected, use:

[edit forwarding-options helpers bootp]
user@switch# set interface ge-0/0/0 server 10.0.0.10

The following steps will set the DHCP Relay function under a routed virtual interface (RVI), so that a DHCP client's request from a VLAN will be forwarded to the connected DHCP server.

1. Create a virtual interface associated with the DHCP relay.

user@switch>set vlans Sales vlan-id 1

2. Create a virtual interface associated with the DHCP relay.

user@switch>set interface vlan unit 1 family inet address 10.0.0.1/24

3. Associate a virtual interface with a VLAN where the DHCP client’s machines will be connected.

user@switch>set vlan default l3-interface vlan.1

4. Associate a virtual interface with the DHCP server under bootp.

[edit forwarding-options helpers bootp]
user@switch@> set interface vlan.1 server 10.10.10.10

Verifying DHCP Relay Operations on EX Switches

• To display the address bindings for extended DHCP relay agent clients:

user@host> show dhcp relay binding

• To display extended DHCP relay agent statistics:

user@host> show dhcp relay statistics

• To clear the binding state of DHCP relay agent clients:

user@host> clear dhcp relay binding

• To clear all extended DHCP relay agent statistics:

user@host> clear dhcp relay statistic

2022-03-11: Modified article title to reflect legacy platforms, and the respective product categories. Article is still relevant.