If you are on a network that has MAC addresses hardwired, i.e. you can only access the network if a certain MAC address is plugged into a specific ethernet jack on the wall, you don’t have too many options.
One option I used recently is spoofing the MAC address of your device. Its done by editing the hardware address to match the MAC address of the device that’s allowed on that ethernet jack.
If you are using Linux, make a note of your current IP address in a text file.
sudo ifconfig -a | grep eth0 > ~/Desktop/netaddressbak.txt
Run the same command on the device that’s attached to the network to find its MAC address: Lets say its – 01:82:39:B2:41:30
Before you attach your new device to the ethernet cable, change its MAC address to the one listed above.
sudo ifconfig eth0 down
sudo ifconfig eth0 hw ether 01:82:39:B2:41:30
sudo ifconfig eth0 up
sudo ifconfig eth0 | grep HWaddr
This should now list the address as 01:82:39:B2:41:30.
You can now attach this device on the network to gain full connectivity (unless there are some programs that are supposed to ping every once in a while).