Slashdot Mirror
Plug In an Ethernet Cable, Take Your Datacenter Offline
New submitter jddj writes: The Next Web reports on a hilarious design failure built into Cisco's 3650 and 3850 Series switches, which TNW terms "A Network Engineer's Worst Nightmare". By plugging in a hooded Ethernet cable, you...well, you'll just have to see the picture and laugh. They write: "The cables, which are sometimes accidentally used in datacenters, feature a protective boot that sticks out over the top to ensure the release tab isn’t accidentally pressed or broken off, rendering the cable useless. That boot would hit the reset button which happened to be positioned directly above port one of the Cisco switch, which causes the device to quietly reset to factory settings."
"There’s an easy way to prevent it happening at all, by disabling the button" Another easy way to prevent this from happening would be DON'T BUY THIS SWITCH
Regardless of the design of the connector, having the reset button directly above the port is a bad design. It's simply too easy to hit it with your thumb just plugging in or removing a cable. I suppose holding it down for several seconds resets to factory, which is what happens when using cables with the boot. Still, regardless of that more severe problem, it was a bad design in the first place.
Better known as 318230.
Are 'config t' and 'write erase' too difficult to remember? Bothered by all those inconvenient keystrokes? Try the new EasyBoot(TM) from Cisco, the most convenient way to reset your router!
Building Better Software
From the article:
The cables, which are sometimes accidentally used in datacenters, feature a protective boot that sticks out over the top to ensure the release
and then
Such a situation could cause a problem in any size datacenter, where these switches and cables are commonly used
So are they commonly used on accident? Accidentally used commonly? I was reading the article to figure out what type of cable was often used, but apparently it's these cables but only by accident all the time.
blah blah blah
Reality is single device failures bring down large chunks of the net including valuable peers of your "enterprise datacenter"
Of course, sometimes identical cisco models used in redundant tuples also cause outages together after upgrade by common bug that didn't show up in test
so pontificate all you want, you're vulnerable to a lot of bad things
The problem is that 3650 and 3850 are not designed for a "Datacenter" deployment.
They aren't even designed as top of rack switches.Their use case is access or distribution for end-users. They belong in a wiring closet.
That, of course, doesn't stop morons or small companies deploying them as "Core" routers or switches in their datacenters....
You're plugging it in wrong.
> If a single device brings down your entire data center, you've got design problems and your architect should be fired or retrained.
Please: if your data center has the time, and skill, and is willing to take the service interruptions to make the whole setup properly immune to single points of failure, that's great. But very, very few live business environments have that kind of resource, time, and willingness to enable critical switches with robust failover.
While I like the auto-LART feature, I wonder what the switch is doing there at all: If the switch is working properly, it doesn't need a reset button.
If the switch is not working properly, it needs to be burdensome to power-cycle it, to encourage people to complain loudly to the responsible vendor(s) until the product actually works.
In these modern times, I think an accessible reset switch is like: "Yo dawg, I heard you like to 'fix' things by pushing buttons, so we put buttons on your Enterprise switches so you can reset one-handed while you [...]"
ObTopic: I once helped take down an enterprise LAN with an Ethernet cable. It was 10-ish years ago, and we just installed a new-fangled VoIP phone system. Each VoIP deskset had a built-in unmanaged 10/100 switch. This was a very handy thing before our modern enlightened structured cabling roll-outs, because it could be trivially daisy-chained with a desktop computer and standardized PoE was not yet a thing.
Anyhow, we started late on a Wednesday, and finished just before start of business Thursday: Record time for replacing an old Nortel with a few hundred extensions, I tell you. And I went home and died on my couch, having been awake and actually working (prep, etc) for about 40 hours.
At 7:23AM, my phone rang. It was my manager. Their entire network had crashed, hard. They blamed us. They were livid. I read my manager the NSFW riot act, hung up, and went back to sleep.
Turns out that after we left, some unknown person had plugged both external switched ports of a deskset into both ports on a wallplate connected to a then high-end HP Procurve switch, which itself connected to a factory and office tower full of other HP Procurve switches carefully set up in a redundant "mesh fabric" mode. This carefully-constructed, redundant network then died in a broadcast packet storm.
Once they found the error and unplugged that one extraneous heads-will-roll wayward wire, things more-or-less instantly returned to normal.
(STP would've instantly made this a complete non-issue, but at that time STP and HP's mesh conflicted with eachother and could not cohabitate. I understand that this was subsequently resolved, though I don't deal with HP switches often enough to verify.)
Kid-proof tablet..