Is it possible to mute the local network?

Question

Computer networks

I came across such an ad on Avito, the description says that it is enough to connect via a patch cord, and the stray will break the entire local network. Is this possible, and if so, how, is it worth worrying about your network, or is it just a hoax?

Answer 1

There are a bunch of ways to put an Ethernet segment. For example, spoofing poppy addresses to fill the switching table, imitation of an L2 loop to drive the switch crazy, replacing gateways with duplicate ARP requests, spamming STP packets, there are also more subtle techniques at the phy-level (there are a very limited number of chips, much less than switch models), but you can go even higher, for example, to fake dhcp. Yes, many things on normal equipment can be cut off, but you need to know about them, and even get confused with fine tuning.
If you want to know how this particular balalaika works, well, ask the seller.

Answer 2

thanks - neighing from the heart.
when they ask about the equipment, everyone unanimously shouts "Mikrotik! Tplink!" and in this topic they say that everyone without exception has a "normally configured network on good equipment." at the same time, one and a half people could at least somehow clearly say for the "correct settings", and even they misrepresented half ...
thanks to you Bermut - your question showed the level of local experts with a huge rating but who do not understand what ICND1 is.
is that possible. ways - a huge number. basic protection - unused ports must be disabled on the switch, DHCP snooping must be enabled on user ports, broadcast restriction must be configured on the equipment, it is desirable to enable Dynamic ARP Inspection and IP Source Guard, segment the network with VLANs, user ports must be in edge mode.

Answer 3

It’s worth worrying about equipment that, when such self-made things are turned on, will not turn off the port before this crap burns it.

Answer 4

If this thing costs about 10,000 rubles, then theoretically yes, it can. But it's not a piece of cable. In a normal network and on a normal industrial, configured switch - NO!