[c-nsp] Cisco RPS for 3550 switch

[Seth Mattinen]

TCIS List Acct wrote:
> 
> Seth Mattinen wrote:
> 
>> Hardware. There is no way to get the device (in my case, some 2811's on 
>> a single RPS-300) to go back to internal power without reloading once 
>> it's switched over to the RPS. Switching back causes the device to lose 
>> power. You should not expect any kind of real redundancy, but expect a 
>> full outage and reload if you ever want to go back to internal AC from 
>> the RPS.
>>
>> Personally, I'd just skip the one to one "redundancy" and just use them 
>> for nothing more than protecting the switch from internal PSU failure, 
>> at which point you'll have to power it down anyway to replace the PSU. 
>> This doesn't affect any other devices plugged into the RPS, only the one 
>> actually drawing power from it.
>>
>> ~Seth
> 
> The RPS-300 is dirt cheap these days (~$50 or less), so 1-1 isn't a big deal for 
> this project.
> 
> I did see somewhere on the archives that someone said pulling the AC power from 
> the RPS (vs using the active/standby buttons) will allow the switch to fail back 
> to its internal P/S without a reboot.  I'll try this when I get our first 
> RPS-300 in and see how it goes.
> 

I've tried it; doesn't work on my gear. I'd always plan for full outage 
though if you ever have to switch back to internal power.

The RPS-600 was so much better than what's being passed off as a 
"redundant" power supply these days... I never bothered using the AC 
input on the device when it was hooked up to a RPS-600 since it had dual 
AC and you could use the dual-head RPS cable to give it redundant DC 
feeds. Truly a redundant power solution for the rest of us. (Totally 
ignoring the 2948G-L3, of course.)

~Seth