Tag Archives: site to site

Wireguard on a USG Pro 4

I ran into some issues when trying to configure an OpenVPN tunnel between my Ubiquiti USG Pro 4 and a Debian VPS. I was very disappointed to discover that the version of OpenVPN on the USG only supports TLS 1.0! My issue was the Debian side rejecting that as insecure.

Thankfully, it was fairly painless to get Wireguard configured on the USG Pro 4. I was hesitant to do so at first because I knew every time my USG was updated I would lose the wireguard pacakge. Fortunately that can be resolved by configuring a post-install script. Thanks to ilar.in and calypte.cc and this github gist for the steps on how to do so.

curl -O https://raw.githubusercontent.com/britannic/install-edgeos-packages/master/install-pkgs
sudo install -o root -g root -m 0755 install-pkgs /config/scripts/post-config.d/install-pkgs
  • Add wireguard DEB package to persistent storage that the script will look for:
sudo mkdir -p /config/data/install-packages
cd /config/data/install-packages
curl -fLSs https://github.com/WireGuard/wireguard-vyatta-ubnt/releases/download/1.0.20200729-1/ugw4-v1-v1.0.20200729-v1.0.20200513.deb
  • Generate a public/private keypair for USG use
cd /config/auth
umask 077
wg genkey > wg_private.key
wg pubkey < wg_private.key > wg_public.key
  • Generate config.gateway.json config to use wireguard
    "interfaces": {
 ...
        "wireguard": {
            "wg0": {
                "address": "<IP_OF_USG_ON_WG_CLIENT_SUBNET>",
                "listen-port": "<WG_LISTEN_PORT>",
                "peer": {
                    "<ENDPOINT_CLIENT_PUBLIC_KEY>": {
                        "allowed-ips": "0.0.0.0/0",
                        "endpoint":  "<ENDPOINT_CLIENT_ADDRESS>:<ENDPOINT_CLIENT_PORT>
"
                    }
                },
                "private-key": "/config/auth/priv.key",
                "route-allowed-ips": false
            },
            "wg1": {
                "address": "<IP_OF_USG_ON_WG_SERVER_SUBNET",
                "firewall": {
                    "in": {
                        "name": "LAN_IN"
                    },
                    "local": {
                        "name": "LAN_LOCAL"
                    },
                    "out": {
                        "name": "LAN_OUT"
                    }
                },
                "listen-port": "<USG_WG_SERVER_LISTEN_PORT>",
                "mtu": "1352",
                "peer": {
                    "<PUBLIC_KEY_OF_WG_CONNECTING_CLIENT": {
                        "allowed-ips": "<SUBNETS_ON_REMOTE_HOST>"
                    }
                },
                "private-key": "/config/auth/wg-server.priv",
                "route-allowed-ips": true
            }
        }
    },

I have two different wireguard interfaces configured – wg0 to be a client to another server, and wg1 to be a server accepting other clients (site-to-site VPN.)

If you want to have multiple peers defined on a single wireguard interface, encapsulate the peers with brackets like so:

"peer": [{
						"--pubkey--": {
							"allowed-ips": [
								"172.255.252.2/32"
							],
							"persistent-keepalive": 60
						}
					},
					{
						"--pubkey--": {
							"allowed-ips": [
								"172.255.252.3/32"
							],
							"persistent-keepalive": 60
						}
					}
				],

Test configuration first

Before committing your config.gateway.json code, test it line by line by SSHing into the USG-Pro 4 and entering config mode. Then type out your JSON lines one at a time, with each key being a new argument separated by a space. The first section above would look like this:

configure
edit interfaces
set wireguard wg0 address WIREGUARD_ADDRESS
set wireguard wg0 listen-port WG_LISTEN_PORT
set wireguard wg0 peer ENDPOINT_CLIENT_PUBLIC_KEY allowed-ips 0.0.0.0/0
set wireguard wg0 peer ENDPOINT_CLIENT_PUBLIC_KEY endpoint ENDPOINT_ADDRESS:ENDPOINT_PORT
set wireguard wg0 private-key /config/auth/priv.key
set wireguard wg0 route-allowed-ips false
commit

If the commit works without error, you can then drop out of the configure section and look at your wireguard config:

exit
sudo wg show

If all looks well, then copy your config.gateway.json to your controller and trigger a reprovision.

Verify after provisioning: 

sudo netstat -npl | grep <WIREGUARD_PORT> | grep udp

Troubleshooting

USG not connecting to changed endpoint address

If you change the address of the wireguard endpoint, USG pro will not connect to that new address. You have to delete and re-create the interface (thanks to https://github.com/Lochnair/vyatta-wireguard/issues/72#issuecomment-423840448 for the information)

Fix this by deleting the wireguard interface

admin@Firewall:~$ configure
[edit]
admin@Firewall# delete interfaces wireguard
[edit]
admin@Firewall# commit


Then reprovision by making a small change, force provision, then change back, and force another provision (annoying) or alternatively reboot firewall.

Wireguard shows established but ping doesn’t work

Example error:

From 10.99.13.1 icmp_seq=5 Destination Host Unreachable
ping: sendmsg: Required key not available

To figure out what’s going on, enable logging to kernel buffer (dmesg) Thanks to procustodibus.com for the info.

echo module wireguard +p > /sys/kernel/debug/dynamic_debug/control

With debug on, ping again and check kernel messages (dmesg)

[Tue Dec 21 22:16:12 2021] wireguard: wg0: No peer has allowed IPs matching 10.99.13.2

This showed I didn’t have my access control properly configured. Modify /etc/wireguard/wg0.conf on your client config and make sure your AllowedIPs are properly letting traffic through.

AllowedIPs = 10.99.13.0/24

USG not allowing connections

Clients unable to connect to USG despite having a good config. Double check your firewall rules. I had neglected to create a WAN LOCAL rule allowing UDP packets on my wireguard port. Once that was configured, handshakes completed successfully.

Firewalls can’t ping each other

I had an issue where the firewalls would pass traffic through, but they couldn’t ping each other. The solution was to add the VPN subnet you created to allowed-ips on both sides of the connection.

Site to site Wireguard VPN between OPNSense & Debian Linux server

I have a Debian linode box acting as a wireguard server. I wanted to join my opnsense firewall to it to allow devices behind it to access the box through the wireguard tunnel. It was not as straightforward as I had hoped, but thankfully I got it all working.

OPNSense side

Documentation link

Install wireguard via GUI

Install the os-wireguard package. Manually drop to the CLI and install the wireguard package as well:
sudo pkg install wireguard

Configure Local instance

  • Name and listen port can be random. Tunnel address is the subnet you wish to expose to the other end (the subnet you wish to have access to the tunnel.)
  • Leave everything else blank and hit save
  • Edit your new connection and copy the Public key, this will need to be sent to the Debian server

Configure Endpoint

  • Name: hostname of Debian server
  • Public Key: Public key of server (can be obtained by running wg show on the server)
  • Shared Secret: blank (unless you’ve configured it on the server)
  • Allowed IPs: IPs or subnets on the Debian server you wish to expose to the client side (the OPNSense box)
  • Endpoint address: DNS name of Debian server
  • Endpoint port: Port Debian wireguard instance is listening on

Enable the VPN

General tab / Enable wireguard checkbox and hit apply.

Debian side

Take down the tunnel

sudo wg-quick down wg0

Edit wireguard config to add peer

sudo vim /etc/wireguard/wg0.conf

[Peer]
PublicKey = <PUBLIC_KEY_YOU_COPIED_IN_LOCAL_INSTANCE_STEP>
AllowedIPs = <IPs or Subnets behind the OPNSense side you wish to be exposed to the Debian side> 

Restart wireguard

sudo wg-quick up wg0

Check connections

Example wg show output below with dummy IPs:

sudo wg show
interface: wg0
  public key: f+/J4JO0aL6kwOaudAvZVa1H2mDzR8Nh3Vfeqq+anF8=
  private key: (hidden)
  listening port: 12345

peer: TuUW7diXcWlaV97z3cQ1/92Zal2Pm9Qz/W2OMN+v20g=
  endpoint: 10.0.0.1:54137
  allowed ips: 10.0.0.2/32
  latest handshake: 17 seconds ago
  transfer: 5.14 KiB received, 3.81 KiB sent

peer: CZuC/+wxvzj9+TiGeyZtcT/lMGZnXsfSs/h5Jtw2VSE=
  endpoint: 8.8.8.8:12345
  allowed ips: 192.168.1.1/32
  latest handshake: 7 minutes, 8 seconds ago
  transfer: 5.89 MiB received, 952.20 MiB sent

The endpoint: line gets populated when a successful VPN connection is made. If it’s missing, the tunnel was not established.

Troubleshooting

OPNSense box

Nothing happens after saving information and enabling tunnel

Make sure latest wireguard package is installed

sudo pkg install wireguard

Get more log output by opening a shell on your OPNSense box and running

sudo /usr/local/etc/rc.d/wireguard start

In my case I was getting this interesting message

[!] Missing WireGuard kernel support (ifconfig: SIOCIFCREATE2: Invalid argument). Falling back to slow userspace implementation.
[#] wireguard-go wg0
┌──────────────────────────────────────────────────────┐
│                                                                                                                                                   │
│   Running wireguard-go is not required because this                                                     │
│   kernel has first class support for WireGuard. For                                                          │
│   information on installing the kernel module,                                                                 │
│   please visit                                                                                                                             │
│         https://www.wireguard.com/install/                                                                           │
└──────────────────────────────────────────────────────┘

I fixed this problem by manually installing wireguard with the pkg install command above.

Debian box

Wireguard config not saving

make sure to stop the tunnel first, otherwise your changes get overwritten by the daemon.

sudo wg-quick down wg0
<make changes>
sudo wg-quick up wg0

OPENVPN site to site vpn between USG and openwrt

A new firewall means a new site to site VPN configuration. My current iteration of this is a USG Pro 4 serving as an OpenVPN server and a Netgear Nighthawk R8000 serving as a VPN client joining their two networks together.

First, I had to wrap my head around some concepts. To set this up you need three sets of certificates and a DH file:

  • CA: To generate and validate certificates
  • Server: To encrypt/decrypt traffic for the Server
  • Client: To encrypt/decrypt traffic from the Client
  • DH: Not a certificate but still needed by the server for encryption

The server and client will also need openvpn configurations containing matching encryption/hashing methods, CA public key, and protocol/port settings.

Generate certificates

If you already have PKI infrastructure in place you simply need to generate two sets of keys and a DH file for the server/client to use. If you don’t, the easy-rsa project comes to the rescue. This tutorial uses easy-rsa version 3.

I didn’t want to generate the certificates on my firewall so I picked a Debian system to do the certificate generation. First, install easy-rsa:

sudo apt install easy-rsa

In Debian easy-rsa is installed to /usr/share/easy-rsa/

Optional: Set desired variables by moving /usr/share/easy-rsa/vars.example to /usr/share/easy-rsa/vars and un-commenting / editing to suit your needs (in my case I like to extend the life of my certificates beyond two years.)

Next, create your PKI and generate CA certificates:

/usr/share/easy-rsa/easyrsa init-pki
/usr/share/easy-rsa/easyrsa build-ca

Now create your DH file. Grab a cup of coffee for this one, it can take up to ten minutes to complete:

/usr/share/easy-rsa/easyrsa gen-dh

Then create your server & client certificates. For this guide we are calling the server ovpn-server and the client ovpn-client

#For the server
/usr/share/easy-rsa/easyrsa gen-req ovpn-server nopass 
/usr/share/easy-rsa/easyrsa sign-req server ovpn-server

#For the client
/usr/share/easy-rsa/easyrsa gen-req ovpn-client nopass
/usr/share/easy-rsa/easyrsa sign-req client ovpn-client

You will be asked for a common name. Remember what you put here, you will need it later. If you just hit enter and accept the default the common name will match what was passed in the above commands (ovpn-server for the server certificate and ovpn-client for the client certificate.)

Lastly, copy these files to their respective hosts:

USG Server: CA, Server key & cert, and DH file. (substitute with IP of your device)

scp pki/dh.pem pki/ca.crt pki/private/ovpn-server.key  pki/issued/ovpn-server.crt admin@IP_OF_YOUR_USG:/config/auth/

OpenWRT Client: Client key & cert, and CA cert:

scp pki/private/ovpn-client.key pki/issued/ovpn-client.crt pki/ca.crt root@IP_OF_YOUR_OPENWRT:/etc/config/

USG: VPN Server

Documentation for the EdgeRouter is much easier to find than for the USG. Since they use the same operating system I based this off of this guide from Logan Marchione for the EdgeRouter. SSH into your USG and issue the following, substituting the $variables with the values you desire for your network.

Explanation of variables:

VPN_SUBNET: Used for VPN communication. Must be different from both server and client subnets.
SERVER_SUBNET: Subnet on server side you wish to pass to client network
VPN_PORT: Change this to desired listening port for the OpenVPN server
REMOTE_SUBNET: Subnet on client side you wish to pass to server network
REMOTE_NETMASK: Netmask of client subnet
REMOTE_VPN_IP: Static IP you wish to give the client on the VPN subnet.
REMOTE_CERT_NAME: Common name given to client certificate generated previously.

Replace $variables below before pasting into USG terminal:

configure
#OpenVPN config
set interfaces openvpn vtun0
set interfaces openvpn vtun0 description "OpenVPN Site to Site"
set interfaces openvpn vtun0 mode server
set interfaces openvpn vtun0 encryption aes256
set interfaces openvpn vtun0 hash sha256
set interfaces openvpn vtun0 server subnet $VPN_SUBNET
set interfaces openvpn vtun0 server push-route $SERVER_SUBNET
set interfaces openvpn vtun0 tls ca-cert-file /config/auth/ca.crt
set interfaces openvpn vtun0 tls cert-file /config/auth/ovpn-client.crt
set interfaces openvpn vtun0 tls key-file /config/auth/ovpn-client.key
set interfaces openvpn vtun0 tls dh-file /config/auth/dh.pem
set interfaces openvpn vtun0 openvpn-option "--port $VPN_PORT"
set interfaces openvpn vtun0 openvpn-option --tls-server
set interfaces openvpn vtun0 openvpn-option "--comp-lzo yes"
set interfaces openvpn vtun0 openvpn-option --persist-key
set interfaces openvpn vtun0 openvpn-option --persist-tun
set interfaces openvpn vtun0 openvpn-option "--keepalive 10 120"
set interfaces openvpn vtun0 openvpn-option "--user nobody"
set interfaces openvpn vtun0 openvpn-option "--group nogroup"
set interfaces openvpn vtun0 openvpn-option "--route $REMOTE_SUBNET $REMOTE_NETMASK $REMOTE_VPN_IP"
set interfaces openvpn vtun0 server client $REMOTE_CERT_NAME ip $REMOTE_VPN_IP
set interfaces openvpn vtun0 server client $REMOTE_CERT_NAME subnet $REMOTE_SUBNET $REMOTE_NETMASK

#Firewall config
set firewall name WAN_LOCAL rule 50 action accept
set firewall name WAN_LOCAL rule 50 description "OpenVPN Site to Site"
set firewall name WAN_LOCAL rule 50 destination port $VPN_PORT
set firewall name WAN_LOCAL rule 50 log enable
set firewall name WAN_LOCAL rule 50 protocol udp
commit

If the code above commits successfully, the next step is to add the config to config.gateway.json. The USG’s config is managed by its Unifi controller, so for any of the changes made above to stick we must copy them to /usr/lib/unifi/data/sites/default/config.gateway.json on the controller (create the file if it doesn’t already exist.)

A quick shortcut is to run the mca-ctrl -t dump-cfg command, then parse out the parts you want to go into config.gateway.json as outlined in the UniFi documentation. For the lazy, here is the config.gateway.json generated from the above commands (be sure to modify $variables to suit your needs.)

{
  "firewall": {
    "WAN_LOCAL": {
      "rule": {
        "50": {
          "action": "accept",
          "description": "OpenVPN Site to Site",
          "destination": {
            "port": "$VPN_PORT"
          },
          "log": "enable",
          "protocol": "udp"
        }
      }
    }
  },
  "interfaces": {
    "openvpn": {
      "vtun0": {
        "description": "OpenVPN Site to Site",
        "encryption": "aes256",
        "hash": "sha256",
        "mode": "server",
        "openvpn-option": [
          "--port $VPN_PORT",
          "--tls-server",
          "--comp-lzo yes",
          "--persist-key",
          "--persist-tun",
          "--keepalive 10 120",
          "--user nobody",
          "--group nogroup",
          "--route $REMOTE_SUBNET $REMOTE_NETMASK $REMOTE_VPN_IP"
        ],
        "server": {
          "client": {
            "$REMOTE_CERT_NAME": {
              "ip": "$REMOTE_VPN_IP",
              "subnet": [
                "$REMOTE_SUBNET $REMOTE_NETMASK"
              ]
            }
          },
          "push-route": [
            "$SERVER_SUBNET"
          ],
          "subnet": "$VPN_SUBNET"
        },
        "tls": {
          "ca-cert-file": "/config/auth/ca.crt",
          "cert-file": "/config/auth/ovpn-client.crt",
          "dh-file": "/config/auth/dh.pem",
          "key-file": "/config/auth/ovpn-client.key"
        }
      }
    }
  }
}

OpenWRT: VPN client

Configuration is doable from the GUI but I found much easier with the command line. I got a lot of the configuration from this gist from braian87b

Install openvpn and the luci-app-openvpn packages:

opkg update
opkg install openvpn luci-app-openvpn

OpenVPN config files are located in /etc/config. In addition to the certificates we copied there earlier, we will also want to copy the openvpn client configuration to that directory.

Here is the config file matching the configuration generated above. Again, remember to replace $variables with your config matching what was generated above. Save it to /etc/config/site2site.conf

#/etc/config/site2site.conf
client
dev tun
proto udp
remote $DNS_OR_IP_OF_USG_OPENVPN_SERVER $VPN_PORT
cipher AES-256-CBC
auth SHA256
resolv-retry infinite
nobind
comp-lzo yes
persist-key
persist-tun
verb 3
ca /etc/config/ca.crt
cert /etc/config/ovpn-client.crt
key /etc/config/ovpn-client.key
remote-cert-tls server

With the openvpn config file, client certificate & key, and CA certificate we are ready to configure firewall rules and instruct the router to initiate the VPN connection.

# a new OpenVPN instance:
uci set openvpn.site2site=openvpn
uci set openvpn.site2site.enabled='1'
uci set openvpn.site2site.config='/etc/config/site2site.conf'

# a new network interface for tun:
uci set network.site2sitevpn=interface
uci set network.site2sitevpn.proto='none' #dhcp #none
uci set network.site2sitevpn.ifname='tun0'

# a new firewall zone (for VPN):
uci add firewall zone
uci set firewall.@zone[-1].name='vpn'
uci set firewall.@zone[-1].input='ACCEPT'
uci set firewall.@zone[-1].output='ACCEPT'
uci set firewall.@zone[-1].forward='ACCEPT'
uci set firewall.@zone[-1].masq='1'
uci set firewall.@zone[-1].mtu_fix='1'
uci add_list firewall.@zone[-1].network='site2sitevpn'

# enable forwarding from LAN to VPN:
uci add firewall forwarding
uci set firewall.@forwarding[-1].src='lan'
uci set firewall.@forwarding[-1].dest='vpn'

# Finally, you should commit UCI changes:
uci commit

Monitor VPN connection progress by using logread. If all goes well you will see the successful connection established message. If not, you’ll be able to get an idea of what’s wrong.

logread -f

If all goes well you’ll now have a bidirectional VPN between your two sites; however, traffic from the server’s subnet going directly to the client router itself (the OpenWRT device’s IP) will be considered as coming from the WAN interface and will be blocked. If you need to access the OpenWRT device directly from the USG’s subnet, you’ll need to add a firewall rule allowing it to do so:

uci add firewall rule
uci set firewall.@rule[-1]=rule
uci set firewall.@rule[-1].enabled='1'
uci set firewall.@rule[-1].target='ACCEPT'
uci set firewall.@rule[-1].src='wan'
uci set firewall.@rule[-1].name='Allow VPN to access router'
uci set firewall.@rule[-1].src_ip='$SERVER_SUBNET'
uci set firewall.@rule[-1].dest_ip='$INTERNALL_IP_OF_OPENWRT_ROUTER'
uci commit

Troubleshooting

One-sided VPN

I fought for some time with the fact that the VPN was established, but only traffic going from the Client network to the Server network would work. Traffic from the OpenVPN server subnet to the OpenVPN client subnet would simply hang and not work.

I finally found on the ubiquiti forums that this is due to default OpenVPN behavior of restricting traffic from the server subnet to the client subnet (see the OpenVPN how-to for more information.) The solution is to add lines in the server config informing it of the client network and to allow traffic to it. Below is an example USG config allowing informing it of remote subnet 192.168.230/24 and assigning the Client an IP of 10.0.76.253:

set interfaces openvpn vtun5 server client client1 ip 10.0.76.253
set interfaces openvpn vtun5 server client client1 subnet 192.168.230.0/24

VPN status stays “stopped” in OpenWRT

The best way to troubleshoot is to look at the logs in realtime. SSH to the OpenWRT router and run the command “logread -f” then try to initiate the connection again. The errors there will point you to the problem.

Site to Site VPN between OPNsense & OpenWRT with Tinc

I’m a real glutton for punishment. I decided to upgrade my parents’ router to OpenWRT. The upgrade went smoothly except for one thing: The VPN I had established between my firewall and theirs.

This was a big enough headache that I even ended up switching my firewall from pfSense to OPNsense (Something I had been contemplating doing for a while anyway) hoping it would make things easier. It didn’t. In the end I abandoned OpenVPN entirely and instead went with Tinc.

Tinc is cool because it’s full mesh peer-to-peer instead of the traditional client / server model. If your equipment supports it, I’d definitely choose it over OpenVPN, especially if multiple sites are involved. A basic rundown of its configuration can be found here.

I used this site as a reference for how to set up tinc.  Essentially you decide on a network name, create private & public keys for each host, and configure each host to connect to each other via a config file & folder structure.

Tinc general configuration

On each device create an /etc/tinc/<network name>/hosts directory structure

mkdir -p /etc/tinc/<network name>/hosts
tincd -n <network name> -K 4096

To configure TINC we need some additional configuration files inside the /etc/tinc/<network name> directory

  • tinc.conf
  • tinc-up (script for bringing up the interface)
  • hosts/<hostname> (one for each location)

tinc.conf can be as simple as this:

Name = <name of host>
ConnectTo = <name of other host> 
#Add each host with an additional ConnectTo line

There needs to be a corresponding file in the hosts directory for each host. Example host file:

Address = <External IP of host>
Subnet = <Subnet other host will share>
#Add more subnets with additional Subnet lines

The host file also need’s the host’s public key. Append it to the end of the file:

cat /etc/tinc/<network name>/rsa_key.pub >> /etc/tinc/<network name>/hosts/<host name>

It’s easiest to generate the host files on each respective host, then copy them to all the other hosts.

The last step is to create the tinc-up script

#!/bin/sh
ubus -t 15 wait_for network.interface.$INTERFACE
ip link set $INTERFACE up ip addr add 172.16.0.1/24 dev $INTERFACE

Modify the IP used on each host so they don’t overlap. The private network here is what’s used for inter-host communication.

Make the script executable:

chmod 755 /etc/tinc/<network name>/tinc-up

OPNSense specific configuration

I got this working through an enhanced tinc package for OPNsense located here.  I will copypasta the content from that site here for easier reference:

Installation

The version might change, adjust it if fetch fails

fetch https://raw.githubusercontent.com/EugenMayer/tinc-opnsense/master/dist/os-tincdcustom-latest.txz
pkg install os-tincdcustom-latest.txz

1. your network

  1. copy the /usr/local/etc/tinc/example folder to /usr/local/etc/tinc/yournetwork
  2. enter yournetwork into /usr/local/etc/tinc/nets.boot to let this network be started on boot
  3. create keypairs by runng tincd -n <yournetwork> -K

2. your network configuration and tun device

  1. Edit /usr/local/etc/tinc/yournetwork/tinc.conf set the server you want to connect to and how this server is to be named
  2. Edit /usr/local/etc/tinc/yournetwork/tinc-up and adjust the network/netbitmask

3. finally the host configuration

  1. enter the /usr/local/etc/tinc/yournetwork/hosts folder and rename the files according to what you have chosen for youservername and theotherservername – they must match!
  2. enter the public key of the “this server” you find under /usr/local/etc/tinc/yournetwork/ into the according thisservernamefile and adjust the subnet this server offers (or subnets)
  3. enter the public key of the “other server” into the according theotherservername file and adjust the subnet the other server offers (or subnets)

4. OPNsense Interface/Gateway/Route/FW configuration

Please see this answer for a brief description

  • You need to create a Gateway, which is configured to go through tinc0 with “dynamic” (do not enter an IP on Gateway field)
  • You need to add a route to <remote subnet> through this gateway
  • Add your tinc0 interface in the Interface section. You can configure a ipv4 address or you don’t, does not matter. If you do, use your tinc-up configured address. Doing this enabled you to create FW Rules for the Tinc interface – which we will need.
  • Add a firewall on the Tinc interface to allow communication to local & remote subnets
    • Alternatively, add a single rule for the Tinc interface to allow any/any access (lazy, less secure)
  • Don’t forget to create a firewall rule allowing the port you’ve configured tinc to run on access from the internet.

OpenWRT specific configuration

Openwrt follows the general tinc configuration exactly. Make the appropriate folders and config files in /etc/tinc/<network name>/ and then test your configuration:

tincd -n <network name>

Once connection is established and working:

Create interface for your VPN (network / interfaces / add new interface) Select the name of your tinc network name from the list.

Next bridge your VPN to the LAN by going to Network / Firewall and editing your LAN zone. Select your VPN interface created earlier from the list and hit save & apply.

Run on startup

I could not find clear documentation on getting this to work on startup. There is a startup script for tinc but it doesn’t appear to launch my tinc config. I ended up modifying /etc/init.d/tinc and adding these lines to the start() and stop() functions. You could also just write your own simple init script to accomplish this.

start() {
...
/usr/sbin/tincd -n <network name>
}

stop() {
...
kill `pidof tincd`
}

Troubleshooting

Tincdcustom service won’t start in OPNSense

Starting from the GUI just does nothing, starting from CLI reveals this unhelpful error:

configctl tincdcustom status

Error (1)

From the OPNSense docs I determined which command I can run to see exactly why. The command is located in this configd configuration file: /usr/local/opnsense/service/conf/actions.d/actions_tincdcustom.conf

command:/usr/local/etc/rc.d/tincdcustom start

Doing that command manually revealed what the problem was:

/usr/local/etc/rc.d/tincdcustom start

Please create /usr/local/etc/tinc/nets.boot.

I had skipped step 1.2 of the tincdcustom instalaltion guide:

enter yournetwork into /usr/local/etc/tinc/nets.boot to let this network be started on boot

Once I added a single word – the name of the network I want to start on bootup – to /usr/local/etc/tinc/nets.boot – the daemon started and worked properly.

Running Tinc in verbose mode

Coming from the tinc documentation, I ran tinc in verbose mode on both of my hosts to troubleshoot why a connection wasn’t happening. It was very helpful.

tincd -n netname -d5 -D

Edit 9/9/2018

I had issues with my tinc startup script not working on the openwrt side. I found here that stated you should add this line to the top of your tinc-up config:

ubus -t 15 wait_for network.interface.$INTERFACE

This solved the startup issue for me.