Why does connecting devices to an ethernet outlet kill the network?

Question

Computer networks

Hello.
The other day I ran into a problem.
So recently, employees began to complain about poor communication (this was especially evident in the RDP connection (friezes and slowdowns)).
At first I sinned on the RDP server, they say there are not enough resources. After long fights and swearing, I decided to throw a direct cable to problem employees, connect directly from the router to a brand new switch, which was supposed to replace the old DES 1016D. As soon as I disconnected the network cable from one ethernet socket, the connection magically returned to normal. RDP got faster, Lotus client began to work faster.
An Ethernet socket, a regular D-Link DES-1005D/RU is connected to it, 3 stationary computers and 1 Ricoh MP2000 are actually connected to it.
The socket itself is routed to a patch panel with which a connection is made to the DLink DES 1016D.
Previously, this outlet also caused problems, but there it immediately laid down the entire network, now it just loaded the grid. Before that, there were no problems for almost a year.
The question is why one small outlet caused such problems and how to prevent them in the future when installing SCS?
There are definitely no loops.

Answer 1

Replace D-Link DES-1005D/RU and socket without going into details.
Is the problem gone? The socket and D-Link DES-1005D / RU in the trash or for spare parts, again without delving into it.
In my house, after 2 years of flawless work, one outlet went crazy. That is, there is no Internet, that is, the connection seems to be, but the address does not work ... Checks, re-probing and poking from the router to the switch at the second end of the wire did not give any result. Stupidly replaced the outlet - the problem is gone. The hand did not rise to throw out, but still overcame himself and threw it away.

Answer 2

The description is very similar to the loop. Check where all the ends of the cables that are connected to the switch connected to this outlet are connected; try replacing the DES-1005, and, of course, the socket.

Answer 3

I encountered inexplicable jokes with wires and sockets. The tester (simple, not Fluk somehow) passes the test, everything seems to be in order - but the ping disappears and that's it. and similar jokes. Therefore, Andrei Ermachenok advises quite correctly.

Answer 4

Faced this. The Chinese VOIP gateway crashed the network on an unmanaged switch. I solved the problem by connecting the client to a managed Cisco 2950.
The answer to your question is to use more expensive equipment in the future.