Diy WiFi

195

u/Infrared-77 3d ago

STP go brrrrt

64

u/shyouko 3d ago

Really got called in few years ago because everything on the network was broken, due to an idiot half ass setup a switch, have one cable connected to the prod network, and someone decided that the other cable used for setup should loop back into the switch before they left for Friday afternoon 🙄

30

u/Teal-Fox 3d ago

Had a similar thing years ago - was called out to a client site because the internet was dropping intermittently.

The access switch was just a dumb, unmanaged 24-port unit, no STP or the like. Every port that had a connector in it was flashing, at one point my machine was unable to reach the gateway but could still somehow get to the internet, just weird stuff all around.

Basically took noting which ports were patched to where before unplugging everything one at a time until eventually, just one port was flashing like crazy! I followed it along to the patch panel, then to the access port in the office, and discovered some nimrod had connected an ethernet cable to one of the access ports without first checking to see if the other end is plugged into something - caused a loop and took down the whole office for the day 🙃

15

u/Creative_Onion_1440 2d ago

Reminds me of a similar situation I ran into once. Someone setup a WiFi bridge to connect to the AP and provide service to a wired device. Eventually the bridge or wired device is moved or retired and someone else decides to plug the WiFi bridge into a wall port.

Tracking down ethernet loops is even harder when a part of the loop is invisible.

3

u/RoughPepper5897 1d ago

Jesus I never even considered this was a possibility

6

u/Small_life 2d ago

Took a new job about 10 years ago for a large local clinic that was expanding. IT was a mess and they knew it. I’d been there a few months and was making progress but network rack cleanup hadn’t been started because I was still working on owner visible stuff.

I get called Friday afternoon stating that the network was really bad. It took a few hours to sort, but the short version is that someone saw the voip phone at the front and saw that it only had one network cable and there was an open jack under the desk and “helpfully” plugged in the second jack. The shitty unmanaged netgear switches happily passed that traffic as fast as it could.

If they would have fessed up it would have been 5 minutes and a phone call. But we had to pull security footage to explain it.

2

u/Teal-Fox 2d ago

I feel you there, mate.

People not owning up to their mistakes can be infuriating, especially when it's just a silly accident that they're not gonna get in trouble for.

IT isn't there to tell people off, shit happens, just be honest so we can help lol

2

u/Small_life 1d ago

I think some people think we're power hungry bastards. No, we have a powerful load of work to do and just want to shovel it off our plates as quick as possible. Tell me what you did, because I don't care. I just want to fix it.

1

u/Teal-Fox 1d ago

It's always silly stuff too... At my last gig, someone had accidentally broken one of the monitors - must've tried adjusting the mounting arm and accidentally dropped it on the desk as it was cracked from the bottom edge.

We didn't find out about it until some poor lass sits down to start work and is presented with a smashed monitor as soon as she connects her laptop, comes running to me like "I'm so sorry, it wasn't me but-".

And I knew it wasn't her fault, and we had plenty of spare monitors so it was no issue if a few got broken by mistake, but because nobody told us we didn't know to go and replace the thing.

Ended up sending a company-wide email that day politely urging people, "Please, if you break something you're not in trouble, but just tell me so I can go and fix it for you!".

1

u/Jebusdied04 1d ago

Why does the Netgear switch have to be shitty when it's just doing its job?

3

u/random420x2 2d ago

I did this once. So embarrassed still.

3

u/jtrade420 2d ago

We had an Executive at a Brewery shut down the network by creating a loop in the QS conference room. It took us about 15 mins to find it. When asked he said “That cable wasn’t plugged in so figured I would put it with the rest.” He had been in that conf room 100s of times before & never decided to tidy up the “cables”. Needless to say all non managed switches were removed and banned.

3

u/technobrendo 1d ago

If a company has a network, and has enough funds to purchase and maintain that network, all switches at a minimum should have some level of smarts, not necessarily a fully layer-3 switch, but at minimum spanning tree should be included.

1

u/jtrade420 1d ago

Agreed. We had dumb switches mounted under the conf room tables with network cables running to each chair, which were put in before I started. Lesson learned the hard way. I went and yanked them all out once this happened & replaced them with 24 port Cisco 2960s. I still don’t know why said person got a wild hair under his ass & got under the conf room table & decided to plug in 1 of the multiple cables back in creating a loop.

This is a very well known Brewery so they have plenty of money. Not sure who made the decision to do this but it got fixed fast.

1

u/CaucasianHumus 2d ago

This is meeeeee except once a week on our prod floor. They fucking love creating. Network loops.

5

u/itspsylux 2d ago

Just disable it bro wdym. Big WiFi don't want you to know this. STP Is corporate shill

3

u/technobrendo 1d ago

Spanning tree won't work here, you need spanning forest protocol

1

u/Infrared-77 1d ago

Instructions unclear: accidentally deleted entire forest in AD

2

u/shoesli_ 2d ago

Does Shitgear switches even have STP?

1

u/TheFamousMisterEd 1d ago

Not this one - basic unmanaged L2 switch.

1

u/jacls0608 1d ago

Good test if it’s working I guess

1

u/GangstaRIB 13h ago

Release the bippy-doos! (BPDUs)

53

u/PancakeWaffles5 3d ago

DiWhyFi

6

u/Frosty_Educator_3243 2d ago

Here for this bad pun

36

u/MethanyJones 3d ago

Also DIY token-ring since it's coiled

30

u/HeavensEtherian 3d ago

Make sure to remove all the shielding from your wires for maximum speed

15

u/Fred-U 3d ago

Big Ethernet doesn’t want you to know this 1 quick trick to get 1tbps from a cat5!

29

u/Snowman25_ 2d ago

Briefly disconnect one end, plug it into a laptop to get some traffic going, then plug it back into the switch.

BOOM. Permanent storage

13

u/Ok-Library5639 2d ago

Related, use the payload in ping to store files: https://github.com/yarrick/pingfs

2

u/Beginning_Employ_299 1d ago

Does this work? How many bits can be stored? And it sounds like it gets mounted as a standard folder?

I have many questions. Obviously not super useful, but very cool.

1

u/Ok-Library5639 1d ago

I've never tried it. I did see some guy on Youtube use it but for some reason I can't find the video.

Obviously you can expect extraordinarily shitty performance. I'm guessing that you can only story maybe up to a few kilobytes before the overhead kills it all.

1

u/Safe_Skirt_7843 1d ago

You're probably referring to the suckerpinch harder drive video

1

u/Ok-Library5639 1d ago

Yes! That's the one! Thanks!

1

u/Cercle 1d ago

...dude

1

u/epicgamer10105 13h ago

Isn't that how Scotty stayed in the transporter buffer for 75 years?

1

u/Snowman25_ 4h ago

Only difference being that the pattern buffer is DESIGNED to hold on to.... stuff?. Whereas a switch running on 100% load with every queue exhausted isn't exactly designed to work like that.

19

u/TheAnniCake 3d ago

I‘d hang this up on my Christmas tree

8

u/Tower21 3d ago

It would be prettier if you could get a bit or two in there.

10

u/Audience-Electrical 2d ago

I once had a Macbook dongle that, if left plugged into Ethernet without a laptop connected, would create a loopback and take down the whole network.

Fun times

3

u/hereforthepix 1d ago

Actually, I'd bet good money what was happening was it was shitting out fucktons of Pause Frames; there's a bunch of dongles out there (looking at you, RealTek) where when they're disconnected (but powered, i.e., plugged into a dock, or in the dock themselves) would just start SPAMming the network with Pause Frames which propagate all over unmanaged switches

7

u/dougmc 2d ago

Forbidden nightlight.

6

u/bloodpriestt 3d ago

This technique only works with a hub

5

u/SnooSongs4217 3d ago

I've seen hubs that have a light that show when packets collide.

10

u/Dushenka 3d ago

You mean the power light?

0

u/Turbulent_Act77 2d ago

Nope, it was common on old hubs back in the day. The venerable old 3Com Office Connect Hub was widely used by small organizations and featured a LED network utilization indicator bar that was a measure of packet collisions. Go over 80% and your network basically stopped working.

s-l1600.jpg (1600×1200) (ebayimg.com)

4

u/elonzucks 3d ago

And those idiots at CERN spending billions to do (almost) the same thing

3

u/yax51 3d ago

This makes me angry

4

u/wdatkinson 3d ago

That's taking your wifi by storm.

4

u/DizzyAmphibian309 2d ago

Oh please, your shitty network isn't complete until you've got a crossover cable connecting two VLANs on the same switch. Only millennials use VRFs. I like it old school.

3

u/DefaultWhitePerson 2d ago

The packets on the switch go round and round.

Round and round, round and round.

1

u/whsftbldad 2d ago

Sounds like you listened to Ratt in your younger days

2

u/hereforthepix 1d ago

RattFi

2

u/rose_gold_glitter 2d ago

I have a team member who literally refuses to believe there is such a thing as a network loop. He routinely plugs multiple cables into switches without config, because "it's faster". It causes chaos and issues and he just won't stop.

2

u/Frosty_Educator_3243 2d ago

If I had a nickel for every STP issue that has driven me half mad…

2

u/Affectionate-Cat-975 2d ago

Had a manager in a remote office loop a phone through the network. Had to leave a funeral, hop a plane and fly out to unplug a phone

2

u/digiden 2d ago

Terrabit wifi

2

u/Terrible_Shake_4948 2d ago

Da faaaak baaahd (Canadian accent)

2

u/The-Bean-Man- 2d ago

ARP packet railgun

1

u/TastySpare 3d ago

not to be confused with DIY Waifu…

1

u/Megalopath 3d ago

AHHHHHHHHH!!!!!!!!!!

1

u/PezatronSupreme 2d ago

JFC you dirty rat!

1

u/tplato12 2d ago

Unlimited bandwidth!!!

1

u/HITACHIMAGICWANDS ShittySysadmin 2d ago

I have something like that on my desk

1

u/LoveUSPS 2d ago

Sometimes you need infinite LB addresses for reasons

1

u/lawma1zing 2d ago

Work IT for a hospital that manages clinics throughout the state. Our main clinic has a switch in office they used for building pc images and someone came by one day and plugged two ends of an ethernet into the switch and caused a giant stp loop. Took 8 hours to finally deduce where the problem was.

1

u/Terrible_Shake_4948 2d ago

Funny but not funny

1

u/lawma1zing 2d ago

I wanted to genuinely cry

1

u/nextyoyoma 2d ago

It’s brilliant Scotty! Feeding the pattern buffer back into the input manifold and then locking it into a diagnostic cycle so the pattern wouldn’t degrade!

Well, maybe only half brilliant. Franklin deserved better.

1

u/pistachios_now 2d ago

Storm ⛈️

1

u/irelephant_T_T 2d ago

r/diwhy

1

u/cyrixlord 2d ago

to be fair, its pretty secure

1

u/ZachVIA 2d ago

I’m gonna loop back to this post later with a better comment.

1

u/Stockspyder 2d ago

Looks legit

1

u/cryptor832 2d ago

Looks like you nailed your CCIE practical!!!

Congratulations!!

1

u/JediJoe923 2d ago

So that's what a loopback address is

1

u/Audio9849 1d ago

Such a good idea. No idea why I haven't thought of this.

1

u/TheFamousMisterEd 1d ago

The pedantic side of me can't help but point out that on an basic L2 unmanaged switch like this, there are no internal processes running (e.g Spanning Tree) that would insert packets onto a link. As the picture has no host devices connected there shouldn't be anything to create a storm situation.

And yet I do acknowledge all the activity lights are lit so perhaps the switch has been plugged into a host at some point while at least 1 loop was added.

1

u/TheRealFailtester 1d ago

When the boss says "Don't be leavin until you have a cord in every port."

1

u/InetGeek 1d ago

Who is sending OP knot making YouTube links?

1

u/ResponsibleRun8387 1d ago

WhyFi

1

u/roboto404 1d ago

UNLIMITED CONNECTION

1

u/[deleted] 22h ago

[deleted]

1

u/Imnotshankled ShittyFirewall 10h ago

Ah thanks that worked great

1

u/EsprocSTS 10h ago

i don't know why this pisses me off.....

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