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Is there any way to check if a network link is physically working, without using ping?


Recently bought a Power-Line-Communication device, and I wanted to test if it works. Before pinging the machines through the PLC, I just tried to connect them with a simple RJ45 cable. Ping or ssh is currently not working, probably because of security rules. Is there any quick way to check if the problem is not from the physical link?...

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    Does you device show the status of its interfaces? – Ron Trunk Jun 24 '20 at 17:26
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    Look at the switch interface to see if it is up. – Ron Maupin Jun 24 '20 at 17:26
  • @RonTrunk After (on a OpenBSD machine) I did an ifconfig enc0 up it shows flags=41<UP,RUNNING> , but this state remains even after unplugging the wire, so doesn't seem very credible... – ymudyruc Jun 24 '20 at 19:29
  • connected switch should have the line protocol as up. – Nish Jun 24 '20 at 23:26
  • Unfortunately, if you are simply connecting host-to-host with a cable, that is really off-topic here because hosts are off-topic, and you have no network devices that we can help you with. Cabling can be tested with a professional cable tester, and, if you do not have one, you can rent one. – Ron Maupin Jun 24 '20 at 23:32
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  1. usually the NIC and switch ports have LEDs that light up, or you could check the port status indicated elsewhere
  2. a connected switch should show the device's MAC address on the port if it has sent just a single frame
  3. run a packet capture on the connected port, usually there's some traffic, or the device even tries to identify itself via LLDP
  4. check the DHCP server if there's a lease for a new device
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Firstly you can check functionality of CAT cable by LAN CABLE TESTERS

Even functionality of cable can be even ensured by verfiying LED lamps of network devices like firewalls ,switches ,routers &NIC card indication lamps on PC's and servers

By verfiying Mac address learning status from connected devices we can ensure connectivity status of devices for example Sh ip arp | I 192.168.X.X is command used in high end layer 3 switches

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