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+started by Ingo Molnar <>, 2001.09.17
+2.6 port and netpoll api by Matt Mackall <>, Sep 9 2003
+Please send bug reports to Matt Mackall <>
+This module logs kernel printk messages over UDP allowing debugging of
+problem where disk logging fails and serial consoles are impractical.
+It can be used either built-in or as a module. As a built-in,
+netconsole initializes immediately after NIC cards and will bring up
+the specified interface as soon as possible. While this doesn't allow
+capture of early kernel panics, it does capture most of the boot
+It takes a string configuration parameter "netconsole" in the
+following format:
+ netconsole=[src-port]@[src-ip]/[<dev>],[tgt-port]@<tgt-ip>/[tgt-macaddr]
+ where
+ src-port source for UDP packets (defaults to 6665)
+ src-ip source IP to use (interface address)
+ dev network interface (eth0)
+ tgt-port port for logging agent (6666)
+ tgt-ip IP address for logging agent
+ tgt-macaddr ethernet MAC address for logging agent (broadcast)
+ linux netconsole=4444@,9353@
+ or
+ insmod netconsole netconsole=@/,@
+Built-in netconsole starts immediately after the TCP stack is
+initialized and attempts to bring up the supplied dev at the supplied
+The remote host can run either 'netcat -u -l -p <port>' or syslogd.
+WARNING: the default target ethernet setting uses the broadcast
+ethernet address to send packets, which can cause increased load on
+other systems on the same ethernet segment.
+NOTE: the network device (eth1 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.