Building a home lab behind a Mac Mini

I wanted to have a lab network in my house seperated from my normal network.
As I allready own a Mac Mini I decided to see if I could use it as router and server for my lab.

1. Adding an interface and enable IP forwarding
2. Enable and configure a DHCP server
3. Enable and configure a TFTP server
4. Enable and configure a NFS server

Adding an interface and enabling IP forwarding

This was relative easy. I just bought a noname USB Ethernet adapter and inserted it into a USB port of my Mac Mini. It showed up as interface en5. I configured it with a static IP address as I did with the build in interface (en0) but for a different subnet.

Then I enabled IP forwarding in the MAC with sysctl -w net.inet.ip.forwarding=1 and to make sure it stays that way after reboots I also edited /etc/sysctl.conf and inserted the line:

net.inet.ip.forwarding=1

And that was all it took to enable the Mac Mini as router. It even works while I load the Mac Mini by playing Civilication VI on it.

Enabling and configuring a DHCP server

Create a DHCP config file with sudo vi /etc/bootpd.plist that looks like this:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
        <key>dhcp_enabled</key>
        <string>en5</string>
        <key>Subnets</key>
        <array>
                <dict>
                        <key>name</key>
                        <string>172.31.155</string>
                        <key>net_mask</key>
                        <string>255.255.255.0</string>
                        <key>net_address</key>
                        <string>172.31.155.0</string>
                        <key>net_range</key>
                        <array>
                                <string>172.31.155.101</string>
                                <string>172.31.155.199</string>
                        </array>
                        <key>allocate</key>
                        <true/>
                        <key>dhcp_router</key>
                        <string>172.31.155.254</string>
                        <key>lease_min</key>
                        <integer>3600</integer>
                        <key>lease_max</key>
                        <integer>86400</integer>
                        <key>dhcp_domain_name_server</key>
                        <array>
                                <string>1.1.1.1</string>
                                <string>8.8.8.8</string>
                        </array>
                </dict>
        </array>
</dict>
</plist>

Then start the DHCP server with sudo launchctl load -w /System/Library/LaunchDaemons/bootps.plist

You can verify the DHCP server is now up with netstat -na|grep "\.67". And my Raspberry PI’s now get an IP address assigned from the range 172.31.155.101-172.31.155.199 where the first PI in the subnet gets 172.31.155.101 assigned.

• man page bootpd section 8
• man page bootptab section 5

Enabling and configuring a TFTP server

Enabling and configuring a NFS server

Other stuff

Current status

Currently this is a work in progress as I build each step I will document it and update this page.

In a sense this is pretty old stuff. I mean, some of it is identical to building a diskless network with Sparc stations. And that is something I did in the early 90’s and dates back even to older times.