The cec command uses raw ethernet frames to connect to a CEC server
to simulate a serial connection. The client and protocol provide
for packet acknowledgement and retransmission. Coraid appliances
and Coraid Plan 9 kernels can currently be CEC servers. Each uses
CEC to provide console access.
A cec process starts by probing the specified network interface
for available CEC servers. The default is /net/ether0 . Only one
cec process may be run per ethernet interface. The –S flag posts
its argument to /srv to allow sharing. If the server is specified
with the –b, –h, or –s flag, the connection will proceed
immediately upon discovery of the first CEC server with the specified
address. Otherwise, a selection prompt will be displayed showing
the discovered CEC servers available for communication. Unless
the –p flag is specified, cec exits if no matching servers are
The selection prompt accepts
0 5 003048865f1e shelf5|
n Connect to server n (from the first column),
p Probe the interface again, and
Note the selection number is not the shelf address but the cec–generated
sequence number printed in the leftmost column.
Once connected to a cec server, entering the escape sequence will
drop the user into an escape prompt where the user may type 'q'
to quit the connection, 'i' to send the escape sequence across
the connection, or '.' to continue the connection. The escape
sequence is printed on connection. If the connection is
unexpectedly lost, the initial probe process outlined above is
–c esc Set the escape caracter to ctl– esc. The default setting is
–d Output debugging information.
–e ea Connect to the server with ethernet address ea.Thisoptionimplies
–h host Connect to the server named host. Note this name may not
be the same as the value of /dev/sysname.
–p Persistence. Continue trying to connect even if there are no
matching servers. This is useful when connecting to a cpu server
before it boots.
–s shelf Connect to the server at shelf address shelf.