3+1 Power redundancy

[epeeler]

Can someone explain how a 6807-XL with 4 power supplies (3+1) behave in the event that 2 power supplies lose their AC input? 

Would it fail to a 1+1 power configuration (the default when you have only two power supplies installed ) and thus only run off of one power supply or would it still understand (for lack of a better word) that it's in a 3+1 configuration and utilize both of the remaining power supplies to power the switch?

Thanks for any insight!

[Masoud Pourshabanian · Accepted solution]

Hello,

It does not fail to 1+1.

1+1 means 1=active, +1= inactive while If you have configured N+1 and one or more of the powers fail,  redundat power(+1) will become active. So in your case, Both of the powers will be active.

In your case, if even two powers fail, your switch will operate normally because the recommendation is 2+1 on a full loaded switch.  2+1 means 2 active and 1 standby.

Please take a look at the table 2 in the link below. (Table 2 PSM Configuration Modes)

http://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst6807xl/hardware/installation/guide/b_c6807xl_hig/b_c6807xl_hig_chapter_01010.html

Hope it helps,

Masoud

[epeeler]

Thanks for the timely and thorough answer Masoud. This is exactly what I needed to know.

Have a great day!

[Masoud Pourshabanian]

Happy to help. You too.

masoud