Documentation/networking/netconsole.rst

1 .. SPDX-License-Identifier: GPL-2.0
25 It can be used either built-in or as a module. As a built-in,
37  netconsole=[+][src-port]@[src-ip]/[<dev>],[tgt-port]@<tgt-ip>/[tgt-macaddr]
41 	src-port      source for UDP packets (defaults to 6665)
42 	src-ip        source IP to use (interface address)
44 	tgt-port      port for logging agent (6666)
45 	tgt-ip        IP address for logging agent
46 	tgt-macaddr   ethernet MAC address for logging agent (broadcast)
66 Built-in netconsole starts immediately after the TCP stack is
68 address.
77    On distributions using a BSD-based netcat version (e.g. Fedora,
79    the -p switch::
81 	nc -u -l -p <port>' / 'nc -u -l <port>
85 	netcat -u -l -p <port>' / 'netcat -u -l <port>
91    socat udp-recv:<port> -
98 parameters reconfigured at runtime from a configfs-based userspace interface.
104 netconsole module (or kernel, if netconsole is built-in).
115 above) and are disabled by default -- they must first be enabled by writing
126 	enabled		Is this target currently enabled?	(read-write)
127 	extended	Extended mode enabled			(read-write)
128 	dev_name	Local network interface name		(read-write)
129 	local_port	Source UDP port to use			(read-write)
130 	remote_port	Remote agent's UDP port			(read-write)
131 	local_ip	Source IP address to use		(read-write)
132 	remote_ip	Remote agent's IP address		(read-write)
133 	local_mac	Local interface's MAC address		(read-only)
134 	remote_mac	Remote agent's MAC address		(read-write)
138 a target can be updated or not -- you can modify the parameters of only
145  echo eth2 > dev_name			# set local interface
150 You can also update the local interface dynamically. This is especially
176  ncfrag=<byte-offset>/<total-bytes>
181  6,416,1758426,-,ncfrag=0/31;the first chunk,
182  6,416,1758426,-,ncfrag=16/31; the 2nd chunk.
190    ethernet address to send packets, which can cause increased load on
196    so it is advised to explicitly specify the remote agents' MAC addresses
201    to find out the MAC address of, say, 10.0.0.2, you may try using::
203 	ping -c 1 10.0.0.2 ; /sbin/arp -n | grep 10.0.0.2
208    the sender, it is suggested to try specifying the MAC address of the
209    default gateway (you may use /sbin/route -n to find it out) as the
210    remote MAC address instead.
226 	dmesg -n 8
231    dmesg(8) man page and Documentation/admin-guide/kernel-parameters.rst