[c-nsp] RPS 675 question

[Peter Rathlev]

On Tue, 2009-08-25 at 16:45 -0400, andrew2 at one.net wrote:
> I'm getting ready to install some RPS 675's in order to dual cord some
> 3750's and ran across this in the manual:
> 
> "Do not use different power sources to power up the RPS and the connected
> device.  If you connect to separate AC power sources, reset conditions might
> occur."

Yes, it's hilarious. Severely limits the usability of the device,
doesn't it? :-)

> Huh?  My intent is to plug the RPS into a different PDU than the actual
> switches so that the switches can stay online in the event of a power
> failure on their primary circuit.  Is this Cisco FUD or are there good
> reasons I wouldn't want to plug an RPS into a different circuit than the
> connected switches?

I guess they say "might occur" either because that had several customers
complaining about something like this or because they looked at the
blueprint and could see some problems with isolation or something.

Generally you can use the RPS the way you describe. Several people,
including me, have been doing it with success e.g. when servicing UPS
devices.

Beware of the possible problems when trying to switch away from the RPS
after the switch starts using it.

This thread might provide more relevant details:

http://www.mail-archive.com/cisco-nsp@puck.nether.net/msg04703.html

Regards,
Peter