I've been trying to set up ethernet at my house, but the ethernet cables I buy online don't seem to work between the router and the main switchboard, although they work between the computer and the wall jack. Only a certain Y-cable, provided to us by the caretaker, seems to work between the router and the switchboard. Could you tell me what the difference between this cable (link 1) and a normal ethernet cable (link 2) is? Both seem to have RJ45 connectors but I've no idea why this one works but a normal one doesn't. I don't care about the telephone part of the wire.
Link 1: https://www.amazon.de/y-kabel4-lan-tae-5m-ST/dp/B01A8DFQ4S/ref=asc_df_B01A8DFQ4S/?tag=googshopde-21&linkCode=df0&hvadid=354526902123&hvpos=&hvnetw=g&hvrand=15769466832269210804&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9043328&hvtargid=pla-791267406937&psc=1&th=1&psc=1&tag=&ref=&adgrpid=68409050541&hvpone=&hvptwo=&hvadid=354526902123&hvpos=&hvnetw=g&hvrand=15769466832269210804&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9043328&hvtargid=pla-791267406937
Link 2: Ugreen Cat7 Flat Shielded RJ45 Ethernet Patch Network Cable 5m Gold Plated Plug STP Wires for High Speed Computer Router Ethernet LAN Networking: Amazon.de: Computer & Accessories
Link 1: https://www.amazon.de/y-kabel4-lan-tae-5m-ST/dp/B01A8DFQ4S/ref=asc_df_B01A8DFQ4S/?tag=googshopde-21&linkCode=df0&hvadid=354526902123&hvpos=&hvnetw=g&hvrand=15769466832269210804&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9043328&hvtargid=pla-791267406937&psc=1&th=1&psc=1&tag=&ref=&adgrpid=68409050541&hvpone=&hvptwo=&hvadid=354526902123&hvpos=&hvnetw=g&hvrand=15769466832269210804&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9043328&hvtargid=pla-791267406937
Link 2: Ugreen Cat7 Flat Shielded RJ45 Ethernet Patch Network Cable 5m Gold Plated Plug STP Wires for High Speed Computer Router Ethernet LAN Networking: Amazon.de: Computer & Accessories