Netconsole

(Updated: Nov 2009)

Netconsole supports kernel-level network logging over UDP. A system request (SysRq) allows users to collect relevant data through netconsole.

To configure netconsole on the 2.6 kernel, complete the following steps.

1. Add the following line to your boot command:

netconsole=[src-port]@[src-ip]/[<dev>],[tgt-port]@<tgt-ip>/[tgt-macaddr]

Command options:

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)

Examples:

linux netconsole=4444@10.0.0.1/eth1,9353@10.0.0.2/12:34:56:78:9a:bc

or

insmod netconsole netconsole=4444@10.0.0.1/eth1,9353@10.0.0.2/12:34:56:78:9a:bc

2. Boot the netconsole machine.

To configure conman over netconsole, complete the following steps.

1. Download conman from http://home.gna.org/conman/

2. Edit /etc/conman.conf to set the SERVER logdir, SERVER logfile, and SERVER port.

3. Add the following to /etc/conman.conf, where clientX is the netconsole machine:

NETCONSOLE name="netconsole" dev="client1_ip_address:client1_port"
NETCONSOLE1 name="netconsole" dev="client2_ip_address:client2_port"
............

4.Start the conmand server by entering

conmand

5. Start the conman netconsole by entering:

conman -d conmand_server_ip:conmand_server_port NETCONSOLEx

6. To see results in the conman netconsole, enter the sysrq command inside the conman console (enter "&", then "S", and then the sysrq command).

Note: A netconsole patch is available that supports kernel level network logging over UDP. More information and a link to the kernel patches can be found at: http://lwn.net/2001/0927/a/netconsole.php3.