Can someone explain this to me?
Some random plugged a loopback into our new 16 port unmanaged switch. For 4 hours our entire internal network was down. Nobody could work. We lost a lot of money, my bosses are furious at themselves. I don't understand the situation, what did they fuck up?
Your packets are stuck in an infinite loop until TTL expires.
This is what you get for not using Schuko power outlets.
A lot of network switches purposefully shut down if you unplug things so you can't fix them easily and are forced to do an expensive service call or keep one key employee around who set it up that way for job security.
I know nothing about networking, but this caught my interest. What cause the service to be available again, or did it just ""fix itself"" after a few hours?
But why did only our internal network come to an halt? Internet was just fine.
Well, its an unmanaged switch with no settings at all other than to distribute ip's from the networks routing tables?
Literally unplugging the cable. (See example in op pic).
But then in a rack with a lot of hardware.
Any switch without loop protection prevention measure with fuck up the network.
Just how it goes.
>The loop createsbroadcast stormsas broadcasts andmulticastsare forwarded by switches out everyport, the switch or switches will repeatedly rebroadcast the broadcast messages flooding the network. Since the Layer 2 header does not support atime to live(TTL) value, if a frame is sent into a looped topology, it can loop forever.
The text didn't copy properly
en.m.wikipedia.org
Lol. I accidentally did this once while setting up my home network and it took me too long to figure out.
Thanks user, pretty clear.
You have no idea of the chaos I witnessed today lol.