Optimizing Ip Performance; Configuration Procedure - H3C MSR 2600 Configuration Manual

Optimizing IP performance

A customized configuration can help optimize overall IP performance. This chapter describes various
techniques you can use to customize your installation.
Enabling an interface to receive and forward
directed broadcasts destined for the directly
connected network
A directed broadcast packet is destined for all hosts on a specific network. In the destination IP address
of the directed broadcast, the network ID identifies the target network, and the host ID is made up of all
ones.
If an interface is allowed to forward directed broadcasts destined for the directly connected network,
hackers can exploit this vulnerability to attack the target network. In some scenarios, however, an
interface must receive and send such directed broadcast packets to support UDP helper and Wake on
LAN.
This task enables an interface to accept directed broadcast packets that are destined for and received
from the directly connected network to support UDP helper, which converts the directed broadcasts to
unicasts and forwards them to a specific server.
The task also enables the interface to forward directed broadcast packets that are destined for the
directly connected network and are received from another subnet to support Wake on LAN, which sends
the directed broadcasts to wake up the hosts on the target network.

Configuration procedure

To enable an interface to receive and forward directed broadcasts destined to the directly connected
network:
Step
1. Enter system view.
2. Enter interface view.
3. Enable the interface to receive
and forward directed
broadcasts destined for the
directly connected network.
Command
system-view
interface interface-type
interface-number
ip forward-broadcast
161
Remarks
N/A
N/A
By default, an interface cannot
receive or forward directed
broadcasts destined for the directly
connected network.