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Layer 2 Bridge

Do you have devices that can't run ZeroTier that you want to access remotely? You can use a small Linux PC as a bridge between ZeroTier and physical networks.


This topic is related to but different from using ZeroTier as a Layer 5 Service Proxy.


  • You're doing this on your home network and can log in to your router and find the DHCP settings.
  • You have a keyboard, monitor, and ethernet cable plugged into your Pi. Chances are high we'll break networking and lose access to the Pi.
  • You're somewhat familiar with the command line and ssh.
  • We're going to use systemd networking for this. You could probably adapt the concepts to a different Linux network configuration system if you have opinions about systemd.
  • We used a Raspberry Pi 2 while writing this, but a Pi 3 or 4 should work fine. Anything running a Debian 10+ based distro should be fine. It doesn't have to be a Raspberry Pi, but some of these instructions might be Raspbian specific.

What you'll need

  • Physical LAN Subnet
  • Physical LAN DHCP Range
  • ZeroTier Auto-Assign Range
  • Default Gateway IP Address (the router)
  • Bridge IP Address (will be statically assigned)
  • Create a new ZeroTier network and get the ID. Keep an old network around for secondary way to connect any devices already using ZeroTier.
  • The DHCP range and ZeroTier Auto-Assign range should be in the same subnet, but not overlap. You'd probably base this off what is already configured on your router.

An example plan

NameValueReferred to below as
Physical LAN Subnet192.168.192.0/24
Physical LAN DHCP RANGE192.168.192.65 through
ZeroTier Auto-Assign Range192.168.192.129 through$ZT_POOL
ZeroTier Managed Route192.168.192.0/23$ZT_ROUTE
Default Gateway IP Address192.168.192.1$GW_ADDR
Bridge IP Address192.168.192.2/24 (or use DHCP)$BR_ADDR
ZeroTier Network IDd5e04297a19bbd70$NETWORK_ID
ZeroTier Network Interface Namezt3jnwghuq$ZT_IF

Get your bridge device up and running

Follow the Raspberry Pi install instructions

SSH into the Pi

It's easier to login via ssh now and copy/paste commands from the comfort of your own PC.

The DNS name might just work for you:

ssh pi@raspberrypi.local Or ssh pi@<ip-address-of-pi>

Update the Operating System

sudo apt update && sudo apt -y full-upgrade && sudo reboot

Log back in after it's done

Install ZeroTier
curl -s | sudo bash

Let's set some shell variables now


Join ZeroTier Network

sudo zerotier-cli join $NETWORK_ID

We don't want ZeroTier to manage addresses or routes on $ZT_IF. We're doing it statically below, on the bridge interface.

sudo zerotier-cli set $NETWORK_ID allowManaged=0

Set one more variable


Copy the dev name from the listnetworks output for $ZT_IF. It will be something like: zt3jvirser

Configure the device in ZeroTier Central

  • Go to the Members section of the Network
  • Open the Wrench Icon for advanced settings and check
  • Check Allow Bridging
  • Check Do Not Auto Assign
  • Authorize the member

Switch to systemd networking

Remove existing network stuff

sudo apt remove --purge --auto-remove dhcpcd5 fake-hwclock ifupdown isc-dhcp-client isc-dhcp-common openresolv

Enable systemd-networkd

sudo ln -sf /run/systemd/resolve/resolv.conf /etc/resolv.conf;
sudo systemctl enable systemd-networkd;
sudo systemctl enable systemd-resolved;
sudo systemctl enable systemd-timesyncd;

Configure interfaces

sudo zerotier-cli set $NETWORK_ID allowManaged=0

Write Network Configuration files. Puts ethernet and zerotier into the bridge and configures the bridge with a static IP. See below for DHCP configuration on the bridge.

cat << EOF | sudo tee /etc/systemd/network/


cat << EOF | sudo tee /etc/systemd/network/br0.netdev

cat << EOF | sudo tee /etc/systemd/network/


cat << EOF | sudo tee /etc/systemd/network/
Name=eth0 # might be en*


Review configuration

tail -n+0 /etc/systemd/network/*

If needed, edit the files with the editor of your preference.

If it looks good:

sudo reboot

You should be able to, from the physical LAN, connect to the Pi via $BR_ADDR

If it takes a long time waiting for the network during boot

Sometimes the physical interface turns out to be a long "predictable interface name" like: "enb827eb0d4176", sometimes it's just eth0, depending on Raspbian version(???).

Hook up a keyboard and monitor and check with ip addr then edit /etc/systemd/network/ to match.

Configure ZeroTier Network


  • Delete the default Managed Route. Add the new Managed Route $ZT_ROUTE
  • Change IPV4 Auto-Assign to Advanced
  • Remove existing Pool. Create new Pool with start and end from $ZT_POOL
  • For documentation purposes, assign $BR_ADDR to the ZeroTier bridge member

It should be working now.

Next steps

Either it worked, and you can ssh back in to $BR_ADDR after a minute, or it didn't work and the Pi isn't on the network anymore and you need to use the keyboard and monitor to figure out what went wrong.


Make a backup of the sd card so you don't have to repeat these steps


Configure bridge with DHCP

cat << EOF | sudo tee /etc/systemd/network/



I can ping the bridge, but not behind it

Sometimes, iptables rules apply: echo "0" > /proc/sys/net/bridge/bridge-nf-call-iptables or iptables -A FORWARD -p all -i br0 -j ACCEPT


Why is the Managed Route /23 and the LAN subnet /24?

Say you have a laptop that is on the ZeroTier network and you bring it home. Now its WiFi address and ZeroTier address are in the same subnet. Which interface/address should your laptop use for internet access?

Why is an app on my phone not working over ZeroTier?

Unfortunately the iOS and Android VPN APIs won't let ZeroTier use multicast/broadcast. These are typically how apps auto-discover services on the LAN. 😭 Stay tuned for an article on bridging a ZeroTier network and a WiFi access point.