3Com OfficeConnect Remote 812 Simultaneous Bridging Routing, Set vc vcname macrouting enable

6-38CHAPTER 6: MANUAL SETUP

MAC-EncapsulatedBecause routers base their forwarding decision on network-level addresses,

Routingpackets that are routed over a WAN are transmitted without MAC-layer addresses. Additionally, address resolution procedures that can be used to determine the destination MAC address for a packet are not required.

Conversely, packets that are bridged over a Wide Area Connection include

MAC-layer information. Address resolution procedures are required.

MAC-Encapsulated Routing uses network-level addresses for forwarding decisions but transmits MAC-layer addresses over the Wide Area Connection. Additionally, address resolution procedures are used. To the remote site, the packets appear as if they had been bridged.

This feature allows the routing features of the OCR 812 (i.e., address translation,

DHCP Server, DNS Proxy, etc.) to be employed in a bridged environment.

Configuring MAC-Encapsulated Routing is specified on a per-VC basis. When MAC-EncapsulatedMAC-Encapsulated Routing is enabled in a VC profile, packets for the routed

Routing protocols configured by the profile (i.e., IP and/or IPX) will be sent using the appropriate bridged encapsulation. If the configured network service is RFC 1483, then the packets will be encapsulated in a bridged-1483 format. If the configured service is PPP, the packets will be encapsulated in BRCP.

To enable MAC-Encapsulated Routing in a VC profile, use the command:

￿set vc <vc_name> mac_routing enable

To disable the MAC-Encapsulated Routing in a VC profile, use the command: set vc <vc_name> mac_routing disable

Simultaneous

Bridging and

Routing

The OCR 812 can be configured for simultaneous bridging and routing. IP routing is configured if IP forwarding is enabled (see Enabling IP Routing). IPX routing is enabled if an IPX network is present over the Ethernet interface (see Configuring IPX for the LAN). Bridging is enabled by adding a bridge network over the Ethernet interface. (see Configuring Bridging for the LAN). Routing and bridging are enabled for each destination in its remote site profile.

When configured for simultaneous bridging and routing, packets received from the LAN are first passed through the router for any configured protocols. If the packet can not be routed it is passed to the bridge depending on the setting of the Bridge Firewall function.

The Bridge Firewall has three modes:

1Discard Routed Protocols:

This is the default mode. If a protocol is configured for routing and a packet for that protocol type is received from the LAN that is not addressed to the MAC address of the OCR 812, it is discarded. Additionally, broadcasts (including ARPs) for the protocol are not passed to the bridge. To configure the Bridge Firewall for this mode, use the command:

set bridge firewall discard_routed_protocols