zrok VPN Guide
zrok VPN backend allows for simple host-to-host VPN setup.
Starting VPN server
VPN is shared through the vpn
backend of zrok
command.
eugene@hermes $ sudo -E zrok share private --headless --backend-mode vpn
[ 0.542] INFO sdk-golang/ziti.(*listenerManager).createSessionWithBackoff: {session token=[589d443c-f59d-4fc8-8c48-76609b7fb402]} new service session
[ 0.705] INFO main.(*sharePrivateCommand).run: allow other to access your share with the following command:
zrok access private 3rq7torslq3n
[ 0.705] INFO zrok/endpoints/vpn.(*Backend).Run: started
sudo
or equivalent invocation is required because VPN mode needs to create a virtual network device (tun
)
-E
option allows zrok
to find your zrok configuration files (in your $HOME/.zrok
)
By default vpn
backend uses subnet 10.122.0.0/16
and assigns 10.122.0.1
to the host that stared VPN share.
$ ifconfig
tun0: flags=4305<UP,POINTOPOINT,RUNNING,NOARP,MULTICAST> mtu 16384
inet 10.122.0.1 netmask 255.255.0.0 destination 10.122.0.1
inet6 fe80::705f:24e4:dcfc:a6b2 prefixlen 64 scopeid 0x20<link>
inet6 fd00:7a72:6f6b::1 prefixlen 64 scopeid 0x0<global>
unspec 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00 txqueuelen 500 (UNSPEC)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 27 bytes 3236 (3.2 KB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
Default IP/subnet setting can be overridden by adding <target>
parameter:
$ sudo -E zrok share private --headless --backend-mode vpn 192.168.42.12/24
VPN share reservation
Share reservation works the same as with other backend types:
eugene@hermes $ zrok reserve private -b vpn
[ 0.297] INFO main.(*reserveCommand).run: your reserved share token is 'k77y2cl7jmjl'
eugene@hermes $ sudo -E zrok share reserved k77y2cl7jmjl --headless
[ 0.211] INFO main.(*shareReservedCommand).run: sharing target: '10.122.0.1/16'
[ 0.211] INFO main.(*shareReservedCommand).run: using existing backend proxy endpoint: 10.122.0.1/16
[ 0.463] INFO sdk-golang/ziti.(*listenerManager).createSessionWithBackoff: {session token=[22c5708d-e2f2-41aa-a507-454055f8bfcc]} new service session
[ 0.641] INFO main.(*shareReservedCommand).run: use this command to access your zrok share: 'zrok access private k77y2cl7jmjl'
[
Accessing VPN share
Accessing a VPN share works similar to other backends.
eugene@calculon % sudo -E zrok access private --headless k77y2cl7jmjl
[ 0.201] INFO main.(*accessPrivateCommand).run: allocated frontend '50B5hloP1s1X'
[ 0.662] INFO main.(*accessPrivateCommand).run: access the zrok share at the following endpoint: VPN:
[ 0.662] INFO main.(*accessPrivateCommand).run: 10.122.0.1 -> CONNECTED Welcome to zrok VPN
[ 0.662] INFO zrok/endpoints/vpn.(*Frontend).Run: connected:Welcome to zrok VPN
Starting zrok access
to a VPN share creates virtual network device/interface:
eugene@calculon ~ % ifconfig
...
utun5: flags=8051<UP,POINTOPOINT,RUNNING,MULTICAST> mtu 1500
inet 10.122.0.3 --> 10.122.0.1 netmask 0xff000000
inet6 fe80::ce08:faff:fe8a:7b25%utun5 prefixlen 64 scopeid 0x14
nd6 options=201<PERFORMNUD,DAD>
...
At this point a VPN tunnel is active between your server and client.
In the example above server is hermes(10.122.0.1)
and client is calculon(10.122.0.3)
.
You can access server from client by using assigned IP address.
eugene@calculon ~ % ssh eugene@10.122.0.1
Welcome to Ubuntu 23.10 (GNU/Linux 6.5.0-27-generic x86_64)
* Documentation: https://help.ubuntu.com
* Management: https://landscape.canonical.com
* Support: https://ubuntu.com/pro
0 updates can be applied immediately.
Last login: Tue Apr 16 09:27:13 2024 from 127.0.0.1
eugene@hermes:~$ who am i
eugene pts/8 2024-04-16 10:04 (10.122.0.3)
eugene@hermes:~$
You can also make a reverse(server-to-client) connection:
eugene@hermes:~$ ssh 10.122.0.3
The authenticity of host '10.122.0.3 (10.122.0.3)' can't be established.
<..snip..>
Warning: Permanently added '10.122.0.3' (ED25519) to the list of known hosts.
(eugene@10.122.0.3) Password:
Last login: Tue Apr 16 09:57:28 2024
eugene@calculon ~ % who am i
eugene ttys008 Apr 16 10:06 (10.122.0.1)
eugene@calculon ~ %