Zyxel VES-1616FE-55A [239/318] Hapter

VES-1616FE-55A User’s Guide

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CHAPTER 43

MAC Force Forwarding

43.1 Overview

MAC force forwarding is a method used to separate subscribers for management purposes.

The VES-1616FE-55A intercepts a subscriber’s ARP (Address Resolution Protocol) requests

and has the subscriber send traffic to a pre-defined Access Router (AR) or Application Server

(AS). The AR or AS routes or forwards subscriber traffic so the subscribers do not know the

MAC addresses of servers on the network. A network administrator can use the AR or AS to

monitor and manage subscriber traffic. This prevents attackers from getting MAC address

information from your network and improves the network bandwidth usage performance.

An example is shown next, MAC force forwarding is disabled at the left. A is a subscriber who

sends an ARP request to ask a server’s (S) MAC address. All subscribers, router (AR), and S

receive a copy from the VES-1616FE-55A (D). S then replies to A’s request. A and S

communicate directly for further data transmission. In this case, all subscribers in the network

can know the servers’ MAC address information.

However, with MAC force forwarding enabled (as shown next at the right), D will reply to A’s

ARP request with AR’s MAC address. A sends traffic to AR. AR forwards the traffic to S. In

this case, none of the subscribers can know S’s MAC address.

Figure 140 MAC Force Forwarding

Without MAC Force Forwarding With MAC Force Forwarding