Setup DHCP server on the USB 3.0 Ethernet

To auto-assign the IP address to the device that connect to the USB 3.0 Ethernet Type-C port of Pi-Cast you will need to setup a DHCP server on the network interface eth0.

The Easy Way

The easy way to set up the onboard USB3.0 Ethernet is using the pre-build image. You can download the image on this link.

Then flash the image to your microSD card. Here is the tutorial for flashing the image.

Manual Way

PiKVMRaspberry Pi OS

Log into PiKVM by ssh.
make the system writeable.
```
rw
```

Edit the file /etc/dnsmasq.conf with the below content.

port=0
interface=eth0
bind-dynamic
domain-needed
bogus-priv
dhcp-range=192.168.2.101,192.168.2.200,12h
dhcp-option=3

Add the below line to the end of the file /etc/fstab.
```
tmpfs /var/lib/misc      tmpfs  mode=0755               0 0
```
Note

Because dnsmasq would write the file /var/lib/misc/dnsmasq.leases when running. But folder /var/lib/misc was mounted as read-only on PiKVM system so dnsmasq wouldn't start success.
Assign static IP to eth0. Change the [Network] section of the file /etc/systemd/network/eth0.network to the following content.
```
[Network]
#DHCP=yes
#DNSSEC=no
Address=192.168.2.1/24
```
Enable the dnsmasq service at startup by the following command.
```
systemctl enable dnsmasq
```
Remount the system as read-only and reboot.
```
ro&reboot&exit
```

Not write yet

Need to write sometime.

After the Pi-Cast booted, connect your computer to the USB3.0 ethernet port of Pi-Cast. Wait a moment, A new network connection will appear and be assigned an IP address starting with 192.168.2. Now you can use the IP address 192.168.2.1 to access your Pi-Cast for the PiKVM webpage or ssh login.

The following image shows an ethernet connection example on MacOS.