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NetBSD 6.1.5 - man page for brconfig (netbsd section 8)

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BRCONFIG(8)			   BSD System Manager's Manual			      BRCONFIG(8)

NAME
     brconfig -- configure network bridge parameters

SYNOPSIS
     brconfig -a
     brconfig bridge
     brconfig bridge command [args ...]

DESCRIPTION
     The brconfig utility is used to configure network bridge parameters and retrieve network
     bridge parameters and status from the kernel.  The bridging function is implemented by the
     bridge(4) driver.

     A network bridge creates a logical link between two or more IEEE 802 networks that use the
     same (or ``similar enough'') framing format.  For example, it is possible to bridge Ethernet
     and 802.11 networks together, but it is not possible to bridge Ethernet and Token Ring
     together.

     Bridge interfaces are created using the ifconfig(8) command's ``create'' sub-command.  All
     other bridge configuration is performed using brconfig.

     The options are as follows:

     -a      Display the status of all bridge devices present on the system.  This flag is mutu-
	     ally exclusive with all other sub-commands.

     All other operations require that a bridge be specified.  If a bridge is specified with no
     sub-commands, the status of that bridge is displayed.  The following sub-commands are avail-
     able:

     up      Start forwarding packets on the bridge.

     down    Stop forwarding packets on the bridge.

     add interface
	     Add the interface named by interface as a member of the bridge.  The interface is
	     put into promiscuous mode so that it can receive every packet sent on the network.

     delete interface
	     Remove the interface named by interface from the bridge.  Promiscuous mode is dis-
	     abled on the interface when it is removed from the bridge.

     maxaddr size
	     Set the size of the bridge address cache to size.	The default is 100 entries.

     timeout seconds
	     Set the timeout of address cache entries to seconds seconds.  If seconds is zero,
	     then address cache entries will not be expired.  The default is 1200 seconds.

     deladdr address
	     Delete address from the address cache.

     flush   Delete all dynamically-learned addresses from the address cache.

     flushall
	     Delete all addresses, including static addresses, from the address cache.

     discover interface
	     Mark an interface as a ``discovering'' interface.	When the bridge has no address
	     cache entry (either dynamic or static) for the destination address of a packet, the
	     bridge will forward the packet to all member interfaces marked as ``discovering''.
	     This is the default for all interfaces added to a bridge.

     -discover interface
	     Clear the ``discovering'' attribute on a member interface.  For packets without the
	     ``discovering'' attribute, the only packets forwarded on the interface are broadcast
	     or multicast packets and packets for which the destination address is known to be on
	     the interface's segment.

     ipf     Enable packet filtering with pfil(9) on the bridge.  The current implementation
	     passes all ARP and RARP packets through the bridge while filtering IP and IPv6 pack-
	     ets through the configured packet filter, such as ipf(4) or pf(4).  Other packet
	     types are blocked.

     learn interface
	     Mark an interface as a ``learning'' interface.  When a packet arrives on such an
	     interface, the source address of the packet is entered into the address cache as
	     being a destination address on the interface's segment.  This is the default for all
	     interfaces added to a bridge.

     -learn interface
	     Clear the ``learning'' attribute on a member interface.

     stp interface
	     Enable Spanning Tree protocol on interface.  The bridge(4) driver has support for
	     the IEEE 802.1D Spanning Tree protocol (STP).  Spanning Tree is used to detect and
	     remove loops in a network topology.

     -stp interface
	     Disable Spanning Tree protocol on interface.  This is the default for all interfaces
	     added to a bridge.

     maxage seconds
	     Set the time that a Spanning Tree protocol configuration is valid.  The default is
	     20 seconds.  The minimum is 1 second and the maximum is 255 seconds.

     fwddelay seconds
	     Set the time that must pass before an interface begins forwarding packets when Span-
	     ning Tree is enabled.  The default is 15 seconds.	The minimum is 1 second and the
	     maximum is 255 seconds.

     hellotime seconds
	     Set the time between broadcasting of Spanning Tree protocol configuration messages.
	     The default is 2 seconds.	The minimum is 1 second and the maximum is 255 seconds.

     priority value
	     Set the bridge priority for Spanning Tree.  The default is 32768.	Allowed numerical
	     values range from 0 (highest priority) to 65535 (lowest priority).

     ifpriority interface value
	     Set the Spanning Tree priority of interface to value.  The default is 128.  The min-
	     imum is 0 and the maximum is 255.

     ifpathcost interface value
	     Set the Spanning Tree path cost of interface to value.  The default is 55.  The min-
	     imum is 0 and the maximum is 65535.

EXAMPLES
     The following, when placed in the file /etc/ifconfig.bridge0, will cause a bridge called
     'bridge0' to be created, add the interfaces 'ray0' and 'fxp0' to the bridge, and then enable
     packet forwarding.  Such a configuration could be used to implement a simple 802.11-to-Eth-
     ernet bridge (assuming the 802.11 interface is in ad-hoc mode).

	   create
	   !brconfig $int add ray0 add fxp0 up

     Consider a system with two 4-port Ethernet boards.  The following placed in the file
     /etc/ifconfig.bridge0 will cause a bridge consisting of all 8 ports with Spanning Tree
     enabled to be created:

	   create
	   !brconfig $int \
	       add tlp0 stp tlp0 \
	       add tlp1 stp tlp1 \
	       add tlp2 stp tlp2 \
	       add tlp3 stp tlp3 \
	       add tlp4 stp tlp4 \
	       add tlp5 stp tlp5 \
	       add tlp6 stp tlp6 \
	       add tlp7 stp tlp7 \
	       up

SEE ALSO
     bridge(4), pf(4), ifconfig.if(5), ifconfig(8), ipf(8), pfil(9)

HISTORY
     The brconfig utility first appeared in NetBSD 1.6.

AUTHORS
     The bridge(4) driver and brconfig utility were originally written by Jason L. Wright
     <jason@thought.net> as part of an undergraduate independent study at the University of North
     Carolina at Greensboro.

     This version of the brconfig utility was written from scratch by
     Jason R. Thorpe <thorpej@wasabisystems.com>.

BSD					 January 7, 2007				      BSD
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