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Network Configuration—Routing and BridgingTo create a bridge, your host should have at least two network cards installed.Creating a bridge is very straightforward as shown here:# ifconfig bridge0 createThis will automatically load appropriate bridging modules into the memory, ifnot compiled in the kernel, and create a virtual bridge interface. Once the interfaceis created, you can add several interfaces into the bridge group, again, using theifconfig utility as follows:# ifconfig bridge0 addm fxp0# ifconfig bridge0 addm fxp1To verify bridge interface configuration and interface membership, ifconfig is used:# ifconfig bridge0bridge0: flags=8802 metric 0 mtu 1500ether e2:72:9e:1e:de:5bid 00:00:00:00:00:00 priority 32768 hellotime 2 fwddelay 15maxage 20 holdcnt 6 proto rstp maxaddr 100 timeout 1200root id 00:00:00:00:00:00 priority 0 ifcost 0 port 0member: fxp0 flags=143member: fxp1 flags=143You can assign an IP address to the bridge interface for remotemanagement reasons. However, it is not advisable to assign IP addressesto bridge members.You can add as many interfaces as you like to a bridge group. However, onlyinterfaces with the same MTU size can be assigned to the same group.To remove an interface from a bridge group, you may use deletem instead ofaddm parameter.Each bridge keeps a table of addresses. It learns from each interface, in order to makethe right forwarding decision. You can display the contents of this table using theaddr command. This is shown in the following command:# ifconfig bridge0 addr00:0b:5f:af:ca:00 fxp1 1073 flags=003:00:00:00:00:0d 0 flags=4600:00:00:1d:02:00 ?? 0 flags=000:00:00:00:00:00 0 flags=000:00:00:00:00:00 828729186 flags=0[ 170 ]