I'd also like to know if Cisco puts voltage protection on the blades? While not exactly the same thing, at my last position we had hundreds of serial terminal servers (Nortel Annex) connected to dumb terminals (all over the country). We found that during bad weather, or other power related issues, the terminal server's serial connections (RJ45) acted as lightning rods. While the terminal server was on APC, the dumb terminals generally were not. When the terminals received a power surge (etc..) they would happily redistribute the jolt to the the serial port and then the terminal server, frying individual ports, blades, and sometimes the entire terminal server. 95% of the time the dumb terminals were fine once the terminal server was replaced. In 2 years we probably replaced 85 of the 350 or so deployed.
Jeremy Porter, CCNP, CCDA -----Original Message----- From: Mossburg, Geoff (MAN-Corporate) [mailto:[EMAIL PROTECTED] Sent: Friday, July 11, 2003 2:42 PM To: [EMAIL PROTECTED] Subject: RE: electrical issues with switches [7:72151] Related to this question: Does Cisco put any kind of voltage protection on the blades? -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Sent: Friday, July 11, 2003 10:47 AM To: [EMAIL PROTECTED] Subject: OT: electrical issues with switches [7:72151] This is completely off topic and, in my case, of an operational nature, so I need to apologize in advance. Unless there is some expressed interest please respond to me privately if you would, thanks. We have suffered over the last couple of years what I would consider an unusually high number of blade failures in various switches (from several vendors including Extreme and Cisco). They have the earmarks of an electrical problem, that is, supplied current spiking and valleying. For instance, where I am located - Northern Virginia - we had some major storms move through last night. This morning I had two blade failures in two separate closets. These closets all have UPS units (usually more than one) and the switches, all of which have dual power supplies, and are split with one power supply going to one UPS, the other to another UPS. Granted both are in the same room and usually plugged into the same circuit. Seemingly this would eliminate, or at least mitigate, the bulk of any electrical fluctuations in the closets. The UPS's have been tested with various diagnostic tools and they appear to check out fine. My question is this. The failures seem to occur more often on densely populated blades (isn't that always the case?). Many people in the building leave their PC's on at night. When the power goes out in this building, the PCs in most areas will also power down. When power is restored, even if it just flickers, all these machines will boot at the same time. Is there any chance that this surge - if there is one - of current coming from the rebooted PC NIC cards could cause these issues? Or is there even a current that flows back from the NIC's (it would seem logical, but I am not an EE). I do realize that I may be grasping at straws. Any thoughts, and again I apologize for the off topic content. There are many bright folks in this group so I thought I would ask. Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=72163&t=72151 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
