BRIDGE(8)

NAME
bridge - netmap client to bridge two netmap ports

SYNOPSIS

bridge
    [-i port] [-b batch size] [-w wait-link] [-v] [-c]

DESCRIPTION
bridge is a simple netmap application that bridges packets between two netmap ports. If the two netmap ports use the same netmap memory region bridge forwards packets without copying the packets payload (zero-copy mode), unless explicitly prevented by the -c flag.

When bridging two physical ports, it is necessary that both NICS are in promiscuous mode, otherwise unicast traffic directed to other hosts will be dropped by the hardware, and bridging will not work.

When bridging the hardware rings of a physical port with the corresponding host rings, it is necessary to turn off the offloads, because netmap does not prepare the NIC rings with offload information. Example:

    ifconfig em0 -rxcsum -txcsum -tso4 -tso6 -lro

Available options:

-i port
    Name of the netmap port. It can be supplied up to two times to identify the ports that must be bridged. Any netmap port type (physical interface, VALE switch, pipe, monitor port...) can be used. If the option is supplied only once, then it must be for a physical interface and, in that case, bridge will bridge the port and the host stack.

-b batch-size
    Maximum number of packets to send in one operation.

-w wait-link
    indicates the number of seconds to wait before transmitting. It defaults to 2, and may be useful when talking to physical ports to let link negotiation complete before starting transmission.

-v  Enable verbose mode

-c  Disable zero-copy mode.

SEE ALSO
netmap(4), lb(8), pkt-gen(8)

AUTHORS
-nosplit bridge has been written by Luigi Rizzo and Matteo Landi at the Universita` di Pisa, Italy.