Optimizing Ip Performance; Enabling An Interface To Forward Directed Broadcasts Destined For The Directly Connected Network; Configuration Procedure; Configuration Example - HPE FlexNetwork 10500 Series 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 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 send such directed broadcast packets to support UDP helper and Wake on LAN.
The task 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. Wake on LAN
sends the directed broadcasts to wake up the hosts on the target network.

Configuration procedure

To enable an interface to forward directed broadcasts destined to the directly connected network:
Step
1. Enter system view.
2. Enter interface view.
3. Enable the interface to
forward directed broadcasts
destined for the directly
connected network.

Configuration example

Network requirements
As shown in
3 of Switch A.
Switch B can receive directed broadcasts from the host to IP address 2.2.2.255.
Figure 53 Network diagram
1.1.1.1/24
Host
Figure 53, the default gateway of the host is the IP address 1.1.1.2/24 of VLAN-interface
Vlan-int3 Vlan-int2
1.1.1.2/24 2.2.2.2/24
Switch A
Command
system-view
interface interface-type
interface-number
ip forward-broadcast
Vlan-int2
2.2.2.1/24
Switch B
139
Remarks
N/A
N/A
By default, an interface cannot
forward directed broadcasts
destined for the directly connected
network.