Allied Telesis AT-WR4500 Bridge Interface Setup, Add ether1 and ether2 to MyBridge interface

78	AT-WR4500 Series - IEEE 802.11abgh Outdoor Wireless Routers
	RouterOS v3 Configuration and User Guide

Quick Setup Guide

To put interface ether1 and ether2 in a bridge.

Add a bridge interface, called MyBridge:

/interface bridge add name="MyBridge" disabled=no

Add ether1 and ether2 to MyBridge interface:

/interface bridge port add interface=ether1 bridge=MyBridge /interface bridge port add interface=ether2 bridge=MyBridge

Specifications

Packages required: system

License required: Level3

Submenu level: /interface bridge

Standards and Technologies: IEEE801.1D

Hardware usage: Not significant

RelatedTopics

•IP Addresses and ARP

•EoIP

Description

Ethernet-like networks (Ethernet, Ethernet over IP, IEEE802.11 in ap-bridge or bridge mode, WDS, VLAN) can be connected together using MAC bridges. The bridge feature allows the interconnection of hosts connected to separate LANs (using EoIP, geographically distributed networks can be bridged as well if any kind of IP network interconnection exists between them) as if they were attached to a single LAN. As bridges are transparent, they do not appear in traceroute list, and no utility can make a distinction between a host working in one LAN and a host working in another LAN if these LANs are bridged (depending on the way the LANs are interconnected, latency and data rate between hosts may vary).

Network loops may emerge (intentionally or not) in complex topologies. Without any special treatment, loops would prevent network from functioning normally, as they would lead to avalanche-like packet multiplication. Each bridge runs an algorithm which calculates how the loop can be prevented. STP allows bridges to communicate with each other, so they can negotiate a loop free topology. All other alternative connections that would otherwise form loops, are put to standby, so that should the main connection fail, another connection could take its place. This algorithm exchange configuration messages (BPDU - Bridge Protocol Data Unit) periodically, so that all bridges would be updated with the newest information about changes in network topology. STP selects root bridge which is responosible for network reconfiguration, such as blocking and opening ports of the other bridges. The root bridge is the bridge with lowest bridge ID.

Additional Resources

http://www.ieee802.org/1/pages/802.1D.html

http://en.wikipedia.org/wiki/IEEE_802.1D

http://ebtables.sourceforge.net/

4.5.2 Bridge Interface Setup

Submenu level: /interface bridge

Description

To combine a number of networks into one bridge, a bridge interface should be created (later, all the desired interfaces should be set up as its ports). One MAC address will be assigned to all the bridged interfaces (the smallest MAC address will be chosen automatically).