Fixing Wired LAN

The scenario is very hard to explain, so I’ll write down what happened and we’ll relate them according to the situation. (*Yaash shrugs).

  1. Connection between my m1 and m2 has been severed. No matter what I do, it can’t establish the connection with the m2 from m1.
  2. So, I deleted the network from my machine. When entering nmcli con show, it won’t display the wired LAN.
  3. Now, the cable is connected from both sides, meaning the devices are connected physically but the ipv4.addresses are not mapped properly.

Steps:

Check the device status

This command will display the devices that are connected to the machine. It can either be a connected or disconnected devices. Now we’ll identify whether the cable is connected and the machine acknowledged it’s connection.

nmcli device status

The output look something similar like this:

DEVICE          TYPE      STATE                   CONNECTION      
enp5s0f4u1      ethernet  connected               mobile-ethernet 
wlp3s0          wifi      connected               JioFi2_A62824   
lo              loopback  connected (externally)  lo              
p2p-dev-wlp3s0  wifi-p2p  disconnected            --              
enp2s0          ethernet  unavailable             --

Now the enp2s0 is the device that have physical connection but no ipv4 address is mapped in it. Let’s fix it!

If the device is not shown in this cmd, make sure the cable is connected properly and try this cmd again.

Add a connection:

Now that we have the name of the device that has connection to the m2 from m1. We have to add the device to the network. For that we need to add many arguements as well, they are:

  • con-name "ethernet" - defines the names of the device.
  • type ethernet - sets the type of the device to ethernet.
  • ipv4.method manual - allows manual ipv4 address mapping.
  • ipv4.addresses <ip.address here> - manually entered IP address goes here.
  • ipv4.gateway - default gateway address that be identified by using ip route. but mention gateway address of the m2.
  • ifname - name of the device given by default.

Let’s add the device now:

sudo nmcli connection add type ethernet con-name "ethernet" ifname enp2s0 ipv4.method manual ipv4.addresses 192.168.10.2/24 ipv4.gateway 192.168.10.1

This is where I messed, up so watch close 👀

  • ipv4.addresses 192.168.10.2/24 - indicates the machine we’re currently using. (i.e m1)
  • ipv4.gateway 192.168.10.1 - indicates the machine that we want establish connection.

Let’s start the connection!

If you did everything right mentioned above, then you’re good to go!

sudo nmcli connection up ethernet