Configuring Arp Fast-Reply; Overview; Configuration Procedure; Arp Fast-Reply Configuration Example - HP FlexNetwork MSR2003 Configuration Manual

Configuring ARP fast-reply

Overview

ARP fast-reply enables a device to directly answer ARP requests according to DHCP snooping
entries. ARP fast-reply functions in a VLAN. For information about DHCP snooping, see
DHCP snooping."
If the target IP address of a received ARP request is the IP address of the VLAN interface, the device
delivers the request to the ARP module. If not, the device takes the following steps to process the
packet:
1. Search the DHCP snooping table for a match by using the target IP address.
2. If a match is found, whether the device returns a reply depends on the type of interface in the
matching entry.
If the interface is the Ethernet interface that received the ARP request, the device does not
return a reply.
If the interface is a wireless interface or an Ethernet interface other than the receiving
interface, the device returns a reply according to the matching entry.
3. If no matching DHCP snooping entry is found, the ARP request is forwarded to other interfaces
except the receiving interface in the VLAN, or delivered to other modules.

Configuration procedure

To configure ARP fast-reply:
Step
1. Enter system view.
2. Enter VLAN view.
3. Enable ARP fast-reply.

ARP fast-reply configuration example

Network requirements

As shown in
the network through the router. The clients obtain IP addresses from the DHCP server through
DHCP.
Enable ARP fast-reply for VLAN 2. The router directly returns an ARP reply without broadcasting
received ARP requests in the VLAN.
Command
system-view
vlan vlan-id
arp fast-reply enable
Figure 6, the router is a DHCP snooping device. All clients are in VLAN 2, and access
Remarks
N/A
N/A
By default, ARP fast-reply is disabled.
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