Mac-Encapsulated Routing; Configuring Mac-Encapsulated Routing; Simultaneous Bridging And Routing - 3Com OfficeConnect Remote 812 Cli User's Manual

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HAPTER ANUAL
MAC-Encapsulated
Routing
Configuring
MAC-Encapsulated
Routing
Simultaneous
Bridging and
Routing
S
ETUP
Because routers base their forwarding decision on network-level addresses,
packets 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.
MAC-Encapsulated Routing is specified on a per-VC basis. When
MAC-Encapsulated Routing is enabled in a VC profile, packets for the routed
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
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:
1 Discard 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