ip relay address cycle

Function

The ip relay address cycle command enables the DHCP server polling function on a DHCP relay agent.

The undo ip relay address cycle command disables the DHCP server polling function on a DHCP relay agent.

By default, DHCP server polling is disabled on a DHCP relay agent.

Format

ip relay address cycle

undo ip relay address cycle

Parameters

None

Views

System view

Default Level

2: Configuration level

Usage Guidelines

Usage Scenario

This command applies to DHCP relay agents. When multiple DHCP server addresses are configured on a DHCP relay agent, the DHCP relay agent forwards DHCP Discover messages to all servers by default. As a result, DHCP servers need to process a large number of messages, leading to heavy loads of servers. To solve this problem, configure the ip relay address cycle command. After this command is configured, the DHCP relay agent forwards a received DHCP Discover message to one DHCP server at a time, and forwards the DHCP Discover message to a different DHCP server each time it receives the message. Multiple DHCP servers then can allocate the same number of IP addresses, implementing load balancing among DHCP servers.

Prerequisites

DHCP has been enabled globally using the dhcp enable command.

Precautions

After the ip relay address cycle command is run, the DHCP relay agent forwards a received DHCP Discover message to a different DHCP server each time in the sequence in which DHCP servers were configured. You can run the display dhcp relay command to view DHCP server IP addresses in the Server IP address field to determine the sequence in which DHCP servers were configured.

Example

# Enable DHCP server polling on the switch in the system view.

<HUAWEI> system-view
[HUAWEI] dhcp enable
[HUAWEI] ip relay address cycle