p The network address of the interface must be specified with an an .Dv SIOCSIFADDR .Xr ioctl 2 before data can be transmitted or received. It is only permissible to change the network address while the interface is marked .Dq down .
p The host's hardware address is discovered by putting the interface in digital loopback mode (not joining the ring) and sending a broadcast packet from which the hardware address is extracted.
p Transmit timeouts are detected through use of a watchdog routine. Lost input interrupts are checked for when packets are sent out.
p If the installation is running .Tn CTL boards which use the old broadcast address of .Ql 0 instead of the new address of .Ql 0xff , the define .Dv OLD_BROADCAST should be specified in the driver.
p The driver can use .Dq trailer encapsulation to minimize copying data on input and output. This may be disabled, on a per-interface basis, by setting the .Dv IFF_NOTRAILERS flag with an .Dv SIOCSIFFLAGS .Xr ioctl . .Sh DIAGNOSTICS l -diag t vv%d: host %d. The software announces the host address discovered during autoconfiguration.
p t vv%d: can't initialize. The software was unable to discover the address of this interface, so it deemed "dead" will not be enabled.
p t vv%d: error vvocsr=%b. The hardware indicated an error on the previous transmission.
p t vv%d: output timeout. The token timer has fired and the token will be recreated.
p t vv%d: error vvicsr=%b. The hardware indicated an error in reading a packet off the ring.
p t en%d: can't handle af%d. The interface was handed a message with addresses formatted in an unsuitable address family; the packet was dropped.
p t vv%d: vs_olen=%d. The ring output routine has been handed a message with a preposterous length. This results in an immediate .Em panic: vs_olen . .El .Sh SEE ALSO .Xr netintro 4 , .Xr inet 4 .Sh HISTORY The .Nm driver appeared in x 4.2 . .Sh BUGS The encapsulation of trailer packets in the x 4.2 version of this driver was incorrect (the packet type was in .Tn VAX byte order). As a result, the trailer encapsulation in this version is not compatible with the x 4.2 .Tn VAX version.