Chapter 17: Ip Multiplexing Overview; Theory And Application; Packet Forwarding Modes - Avaya 1000 Series Configuration Manual

Chapter 17: IP MULTIPLEXING OVERVIEW

Theory and Application

IP Multiplexing is a method for the transparent forwarding of IP packets between LAN and
WAN interfaces. LAN to WAN forwarding is accomplished through a Proxy ARP process. A
Secure Router maps a unique MAC address to each WAN link then responds with this MAC
address when a device on the LAN broadcasts an ARP request for a remote device. These
MAC addresses serve as "tags" for forwarding packets received on the LAN. WAN to LAN and
WAN to WAN forwarding is based on configured forwarding entries.
IP Multiplexing differs from bridging and switching in that it does not flood traffic or perform
address learning. IP Multiplexing devices differ from routers in that they do not appear as a
router hop, and they cannot be specified as a default router/gateway on a LAN.

Packet Forwarding Modes

There are two modes for WAN to LAN and WAN to WAN packet forwarding
• IP Routes – Forwarding based on routing statements, both specific and default.
• Source Forwarding – Forwards all traffic arriving on a specified WAN bundle to a specified
device on the LAN.
The following table provides information about applications and a suggested forwarding mode
for each.
Table 12: Applications and Suggested Forwarding Modes
Forwarding traffic from different WAN links to separate
routers on the LAN
Forwarding all WAN traffic to a single router on the
LAN
Forwarding to both LAN and WAN router
Avaya Secure Router 1000 Series Configuration Guide
Application Suggested Forwarding Mode
Source Forwarding
Default IPMux Routes
Specific IPMux Routes
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