System information

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Appendix

Gratuitous Address Resolution

Protocol Protection

Gratuitous Address Resolution Protocol (GARP) Protection prevents the

IP Phone from GARP Spoof attacks on the network. In a GARP Spoof

attack, a malicious device on the network takes over an IP address

(usually the default gateway) by sending unsolicited (or Gratuitous) ARP

messages, thus manipulating the ARP table of the victim machine. The

malicious device launches a variety of attacks on the network, that results

in undesired traffic routing. For example, a GARP attack can convince the

victim machine that the malicious device is the default gateway. In this

scenario, all traffic from the victim machine flows through the malicious

device.

Nortel Communication Server 1000

IP Phones Fundamentals

NN43001-368 05.02 26 May 2009