Configure DHCP Relay

Before you begin

If the agent IP address is a VLAN or port IP address, you must enable DHCP Relay on that VLAN or port within the VLAN context. However, if the agent IP address is a VRRP address, you do not need to enable DHCP Relay on the VLAN or port in which the VRRP address resides.

About this task

After you configure the BOOTP/DHCP relay on an IP interface, you can configure forwarding paths to indicate where packets are forwarded. The forwarding paths are based on the type of packet and where the packet is received.

Procedure

  1. In the navigation pane, expand Configuration > IP.
  2. Select DHCP Relay.
  3. Select the Globals tab.
  4. Select Insert.
  5. In the AgentAddr box, type the agent address.
  6. In the ServerAddr list, type the server address.
  7. Select Enable to enable BOOTP/DHCP relay.
  8. In the Mode box, select the type of messages to relay.

    Both the mode setting for the DHCP interface and the mode setting for the agent interface determine which packets are forwarded.

  9. Select SrcPort67 to configure the source port for the BOOTP/DHCP relay request.
  10. Select Insert.

Globals Field Descriptions

Use the data in the following table to use the Globals tab.

Name

Description

AgentAddr

Specifies the IP address of the input interface (agent) on which the BOOTP/DHCP request packets are received for forwarding. You cannot specify a Secondary IP Interface address as the agent IP address in the forwarding path. To make DHCP aware of Secondary IP Interfaces, you must enable DHCP Smart Relay.

ServerAddr

This parameter is either the IP address of the BOOTP/DHCP server or the address of another local interface.

  • If it is the address of the BOOTP/DHCP server, the request is unicast to the server address.

  • If the address is one of the IP addresses of an interface on the system, the BOOTP/DHCP requests are broadcast out of that local interface.

Enable

Enables BOOTP/DHCP relay.

Mode

Specifies the type of messages relayed:

  • Only BOOTP

  • Only DHCP

  • Both types of messages

The default is to forward both BOOTP and DHCP messages.

SrcPort67

Assigns source port 67 to the UDP forwarding path. The default is source port 68.