4000 Router Series Security Configuration Guide

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Configuring ARP attack protection

ARP attacks and viruses are threatening LAN security. This chapter describes multiple features used to

detect and prevent ARP attacks.

Although ARP is easy to implement, it provides no security mechanism and is vulnerable to network

attacks. An attacker can exploit ARP vulnerabilities to attack network devices in the following ways:

• Acts as a trusted user or gateway to send ARP packets so the receiving devices obtain incorrect ARP

entries.

• Sends a large number of IP packets for which ARP cannot find corresponding MAC addresses

(called unresolvable IP packets) to have the receiving device busy with resolving IP addresses until

its CPU is overloaded.

• Sends a large number of ARP packets to overload the CPU of the receiving device.

For more information about ARP attack features and types, see ARP Attack Protection Technology White

Paper.

ARP attack protection configuration task list

Tasks at a

lance

Flood prevention:

• Configuring unresolvable IP attack protection (configured on gateways)

{ Configuring ARP source suppression

{ Enabling ARP blackhole routing

• Configuring ARP packet rate limit (configured on access devices)

• Configuring source MAC-based ARP attack detection (configured on gateways)

User and gateway spoofing prevention:

• Configuring ARP packet source MAC consistency check (configured on gateways)

• Configuring ARP active acknowledgement (configured on gateways)

• Configuring authorized ARP (configured on gateways)

• Configuring ARP detection (configured on access devices)

• Configuring ARP automatic scanning and fixed ARP (configured on gateways)

• Configuring ARP gateway protection (configured on access devices)

• Configuring ARP filtering (configured on access devices)

IMPORTANT:

The following features are not supported in the current release, and they are reserved for future use:

• ARP packet rate limit.

• ARP detection.

• ARP gateway protection.

• ARP filtering.