Whenever I plug a console cable into the back of my sunfire v240 it automatically turns of bge0 which is the interface that connects to my network and the only interface i use on the box (and it stays shutdown until reboot). Is there anyway to stop this from happening or can someone please explain why it does that? I have yet to find any info on it..
A quick Google search turns up a related answer for this one:
http://www.sunmanagers.org/pipermail/summaries/2003-December/004627.html
Neo
I've dealt with this hardware but never come across that, it sounds like a hardware issue. I assume you don't have a support contract if you're posting here.
All I can suggest is using the network management port instead, I know that's not much help but all I can think of.
edit:
I may be missing something but what does that have to do with the problem? 
Are you using the ethernet mgt port or the serial port?
What do you mean by "turns it off"? does it show as DOWN with ifconfig? Unplumbs it?
Any messages?
I'm running Solaris 9 on a Sun v240 box. When I plug into serial mgt port shown here (http://docs.sun.com/source/819-4208-10/figures/admin_intro-13.gif\) as soon as I plug into that port and run hyperterm it shuts down my network interface bge0 so I can't telnet/ping/login etc.... I then have to from the ok prompt (in hyperterm) issue the boot command to restart the server then the interface comes back up and all is well. I've never seen this before and I'm not sure the link that was given above has to do with what im asking. Is this some kind of power management thing? I don't really think i have any broken hardware just some wacky config or something.
Oh and the part of the reason why i can't plumb and such is there isn't a video or keyboard port so if i don't have ssh then its console or nothing.
I probably should have posted this in the network section instead of this one sorry about that... UGH!
Ok, so let me get this straight...
You plug in the cable, and you run hyperterminal ( I take it you are using a laptop/WS with Windows?).
When hyperterminal comes up, are you getting an ok prompt or a login prompt?
If you are getting an ok prompt, then you are sending a break signal to the box, which is bringing the whole box to a halt, not just your interface.
Before I do anything "break or boot" command it turns off the bge interface i'm not sure if it is locking the whole machine or just turning off the network interface or what. I consoled into my one server to make sure I had my hyper terminal settings correct then 5 seconds later I got an email letting me know bge0 was down on that device I didn't even type a command i think i hit enter once or twice that was it my screen looked like this below.
OK
OK
OK
then i disconnected and walked away without entering anything in console but a few enters...
Yes, I am using winxp/laptop/console cable to serial etc...
When hyperterminal comes up and you hit enter, you should be seeing a login prompt, not an OK prompt. You are indeed sending a break signal - albeit involuntary - to the box and bringing the whole thing to a halt.
Sending a break signal on the system console causes the OS to drop into firmware mode and issue an "OK" prompt. Want the OS to start running again? Just type this command:
go
The reason is that Sun thought it would be cool if you could drop the machine to firmware mode by just unplugging and reconnecting the system console. It is possible for the OS to change this behaviour a second or two after a reboot, but there is still a very tiny window during boot where a break will work.
For solaris 2.6 get patch 105924-10 or later
For solaris 7 get patch 107589-02 or later
After solaris 7, no patch is needed.
Then modify /etc/default/kbd to have line like:
KEYBOARD_ABORT=alternate
Then after next reboot, you drop to firmware with ~^b (tilde, control-b)
There is also a kbd command to do this on the fly.
Ahhhhh.... Thanks a lot, I will mess around with that and see how it works.
You can plug-unplug terminals into any Sun box and it's not going to go to the ok prompt just for that.
The problem used to be that, if you powered off the terminal before disconnecting the serial cable, or powered on the terminal after connecting the serial cable, that would send a break signal to the console, thus bringing the box to the ok prompt.
Hmm, have you ever tried it when the console is a keyboard? Also the electrical glitch of unplugging a serial console can do this and as Perderabo already mentioned it was patched so the key sequence could be a little more complex resloving many of these issues. I have personally seen this happen in the past 12 months with the standard break enabled.
Literary hundreds of times using workstations, laptops, wyse terminals, xyplexes, etc. to connect to the serial console, for years.