R2511-HP MSR Router Series Security Configuration Guide(V5)

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Configuring ARP packet source MAC consistency
check
This feature enables a gateway to filter out ARP packets whose source MAC address in the Ethernet
header is different from the sender MAC address in the message body, so that the gateway can learn
correct ARP entries.
To enable ARP packet source MAC address consistency check:
Ste
p
Command Remarks
1. Enter system view.
system-view N/A
2. Enable ARP packet source MAC
address consistency check.
arp anti-attack valid-check enable Disabled by default.
Configuring ARP active acknowledgement
Configure this feature on gateway devices to prevent user spoofing.
ARP active acknowledgement prevents a gateway from generating incorrect ARP entries. For more
information about its working mechanism, see ARP Attack Protection Technology White Paper.
To configure ARP active acknowledgement:
Ste
p
Command Remarks
1. Enter system view.
system-view N/A
2. Enable the ARP active
acknowledgement function.
arp anti-attack active-ack enable
Disabled by default.
Configuring ARP automatic scanning and fixed ARP
ARP automatic scanning is usually used together with the fixed ARP feature.
With ARP automatic scanning enabled on an interface, the device automatically scans neighbors on the
interface, sends ARP requests to the neighbors, obtains their MAC addresses, and creates dynamic ARP
entries.
Fixed ARP allows the device to change the existing dynamic ARP entries (including those generated
through ARP automatic scanning) into static ARP entries. The fixed ARP feature effectively prevents ARP
entries from being modified by attackers.
Use both ARP automatic scanning and fixed ARP in small-scale networks such as a cybercafe.
Configuration guidelines
When you configure ARP automatic scanning and fixed ARP, follow these guidelines:
• IP addresses existing in ARP entries are not scanned.