
started by Ingo Molnar <mingo@redhat.com>, 2001.09.17

the network console can be configured over the module interface,
by specifying the dev=, target_ip=, source_port=, target_port=
module parameters. Sample use:

insmod netconsole dev=eth0 target_ip=0x0a000701 \
                  source_port=6666 target_port=6666

IP addresses must be specified in hexadecimal numbers. The
above example uses target host IP 10.0.7.1.

if the module is loaded then all kernel messages are sent to the
target host via UDP packets. The remote host should run the
client-side 'netconsole' daemon to display & log the messages.

WARNING: the default setting uses the broadcast ethernet address
to send packets, which can cause increased load on other systems
on the same ethernet segment. If this is not desired, then the
target ethernet address can be specified via the target_eth_byte0,
target_eth_byte1 ... byte5 module parameters. Eg.:

insmod netconsole dev=eth0 target_ip=0x0a000701 \
                  source_port=6666 target_port=6666 \
                  target_eth_byte0=0x00 \
                  target_eth_byte1=0x02\
                  target_eth_byte2=0xA5 \
                  target_eth_byte3=0x13 \
                  target_eth_byte4=0x51 \
                  target_eth_byte5=0xDD

will instruct the netconsole code to use target ethernet address
00:02:A5:13:51:DD.

NOTE: the network device (eth0 in the above case) can run any kind
of other network traffic, netconsole is not intrusive. Netconsole
might cause slight delays in other traffic if the volume of kernel
messages is high, but should have no other impact.

netconsole was designed to be as instantaneous as possible, to
enable the logging of even the most critical kernel bugs. It works
from IRQ contexts as well, and does not enable interrupts while
sending packets. Due to these unique needs, configuration can not
be more automatic, and some fundamental limitations will remain:
only IP networks, UDP packets and ethernet devices are supported.
