bridge – Ethernet bridge and IPv4 tunnel
bind –a #Bb /net
The bridge device bridges (copies) packets amongst Ethernet interfaces.
The number b in the bind is optional and selects a particular
bridge (default 0).
The /net/bridge0 directory contains ctl, cache, log, and stats files, and numbered subdirectories for each physical interface.
Opening the ctl file reserves an interface. The file descriptor
returned from the open(2) will point to the control file, ctl,
of the newly allocated interface. Reading ctl returns a text string
representing the number of the interface. Writing ctl alters aspects
of the interface. The possible ctl messages are:
bind ether name ownhash path
delay delay0 delayn
clear option Clear bridge option.
Reading stats returns statistics about the bridge.
Reading the log file returns data from the bridge's log and will block at end of file awaiting new data.
Reading the cache file prints the cache of (destination MAC address, port) tuples, one entry per line. The format is: the destination MAC (e.g., Ethernet) address in hex, port number, count of packets from this address, count of packets to this address, expiry time in seconds since the epoch, and e for expired entries or v for valid entries.
In a connection subdirectory, ctl and local don't do anything,
but status returns a one–line status summary.
Set up a network bridge between two Ethernets (#l0 and #l1).
Understands but won't tunnel nor fragment IPv6.