signal sent on network turning on/off

G4tsu · 11-04-2008, 11:03 AM

Hi,
Anyone knows if there is any signal that kernel sends when network goes up/down?
Thx

TB0ne · 11-04-2008, 11:40 AM

Quote:

Originally Posted by G4tsu

Hi,
Anyone knows if there is any signal that kernel sends when network goes up/down?
Thx

Yes...this is where the messages in your syslog come from, when a link goes up or down.

http://linux.die.net/man/8/ifplugstatus

....should explain more. Note that this is for the connection only; if someone unplugs a cable, you'll get something. If the switch you're plugged in to is up, but someone removes it's upstream connection, you won't get anything...the link is still active, but just doesn't go anywhere.

Your question said when the network goes up/down....lots of parts to a network....

G4tsu · 11-05-2008, 03:06 AM

Uhm I am not sure that tool can help me... It seems a command line tool...

Instead what I would need is a signal (such as SIGCHLD, SIGUSR1, SIGSEV, ecc) sent to a daemon of mine when cable is plugged...

TB0ne · 11-05-2008, 08:13 AM

Quote:

Originally Posted by G4tsu

Uhm I am not sure that tool can help me... It seems a command line tool...

Instead what I would need is a signal (such as SIGCHLD, SIGUSR1, SIGSEV, ecc) sent to a daemon of mine when cable is plugged...

Ok....so get the source for that, and use the parts you need for your program. Or have your program monitor the system logs for a LINK-UP/DOWN event....