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New Member

Power Question

At our sites we have anywhere from a single switch to 5 switches depending on the size of the site. When there is a power loss, the switches will stay powered until the UPS at eac site runs out of charge. Is it bad for the power supply on a switch or the circuits within the switch to pwered off like this?

For that matter, is it bad just to pull the plug out of the back of a switch when powering down?

thanks, Pat.

Everyone's tags (2)
11 REPLIES
Hall of Fame Super Gold

Power Question

Should be fine Patrick.

New Member

Power Question

Is a switch designed to be powered off by pulling the plug?

Hall of Fame Super Gold

Power Question

You can either leave the power plug on or off.  It doesn't matter.  The switch can "tolerate" either.

You can verify the status of the power-up by performing a very simple command "sh post". 

New Member

Power Question

I don't understand what you mean. What does leaving the power plug on or off mean?

Thanks, Pat.

Hall of Fame Super Gold

Power Question

You can leave the appliance plugged to the power source when the power goes on/off. 

VIP Super Bronze

Power Question

Pat,

Most small switches (2600, 3600, 3700) don't come with a power switch.  So, in order to turn them off you have to just pull out the power cord.  Bigger switches (4500, 6500.etc..) have actually a switch to turn on and off each power supply. As Leo said they should be able to tolerate the power disconnect.  Regardless of power outage or purposely turning off the switch, this is the only way to tun off or on a Cisco switch. Another word, there is no graceful shut down like in Unix/Linux OS based environment.

HTH

New Member

Power Question

Thanks for the responses. I just think it is weird that we just pull the plug on the switches. Seems kinda cave man.

Hall of Fame Super Gold

Power Question

Thanks for the responses. I just think it is weird that we just pull the plug on the switches. Seems kinda cave man.

There's another way ...

You can try console servers with power.  Try WTI.

Super Bronze

Re: Power Question

Disclaimer

The  Author of this posting offers the information contained within this  posting without consideration and with the reader's understanding that  there's no implied or expressed suitability or fitness for any purpose.  Information provided is for informational purposes only and should not  be construed as rendering professional advice of any kind. Usage of this  posting's information is solely at reader's own risk.

Liability Disclaimer

In  no event shall Author be liable for any damages whatsoever (including,  without limitation, damages for loss of use, data or profit) arising out  of the use or inability to use the posting's information even if Author  has been advised of the possibility of such damage.

Posting

re: "cave man"  It's actually the opposite.  Saves the vendor the cost of including a power switch.  If you think about it, not much expected routine use for turning power on and off, either the network device is being used or not.  "Cave man" was always providing a power switch even if there was little need.

In theory a power switch should break the power cleanly while pulling a plug might cause power to go off/on/off (etc.) as you remove the plug but this matters little.  As others have noted, doesn't cause any harm.

PS:

As Reza noted, operating systems often have a graceful shutdown.  This because they often have pending file system writes and an abrupt power shutdown would often leave their file systems "corrupted".

Incidentally, today may computer systems will power themselves off at the end of a "shutdown" command, but in times past you had to power them off manually even after telling them to shutdown.

On most later generation PCs, the power button isn't really a power switch.  It indicates to the system whether you want it to power itself off/on.  Depending on how its designed, I've seen PCs with such power buttons get so "confused" that I still needed to pull the plug to power the system off; often to reboot it.

Oh, and if you think saving costs don't matter to vendors, its also why most PCs never included a hardware reset switch, although hardware by design generally supports it.  Much less expensive than an actual power switch, but vendors look at cost vs. what they think you need (or want).  This was generally true for hardware reset switches unless you're doing low level driver development.

New Member

Power Question

Wow! Thanks for handing my ass to me.

Question: Then why include the power switch on routers?

Thanks, Pat.

Super Bronze

Re: Power Question

Disclaimer

The   Author of this posting offers the information contained within this   posting without consideration and with the reader's understanding that   there's no implied or expressed suitability or fitness for any purpose.   Information provided is for informational purposes only and should not   be construed as rendering professional advice of any kind. Usage of  this  posting's information is solely at reader's own risk.

Liability Disclaimer

In   no event shall Author be liable for any damages whatsoever (including,   without limitation, damages for loss of use, data or profit) arising  out  of the use or inability to use the posting's information even if  Author  has been advised of the possibility of such damage.

Posting

Patrick McHenry wrote:

Wow! Thanks for handing my *** to me.

Question: Then why include the power switch on routers?

Thanks, Pat.

Only Cisco could really answer that - but perhaps since they have more "features" than a switch (laugh).

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