Ubuntu 18.04 offers OpenVPN as the only already available VPN method in GNOME graphical interface.
sudo apt-get update
sudo apt-get install network-manager-l2tp
sudo apt-get install network-manager-l2tp-gnome
This will add to your Ubuntu network manager and GNOME all the L2TP features. Now just follow the steps:
- Go to Settings -> Network -> VPN. Click the [+] button.
- Select the Layer 2 Tunneling Protocol (L2TP).
- Enter anything you like in the Name field: Router VPN
- It can be any name.
- Enter Your VPN Server Address for the Gateway: yourname.duckdns.org or IP.
- If you don’t have a static IP is recommended to use a dynamic DNS service, such as DuckDNS [http://duckdns.org/] that is absolutely free forever!
- Enter Your VPN Username for the User name: username
- Configure the same user on the server-side.
- Right-click the [?] in the Password field, select Store the password only for this user.
- Enter Your VPN Password for the Password: *******
- Configure the same password on the server-side.
- Leave the NT Domain field blank.
- Click the IPsec Settings button.
- Check the Enable IPsec tunnel to L2TP host checkbox.
- Leave the Gateway ID field blank.
- Enter Your VPN IPsec PSK for the Pre-shared key: a2N4uPNl1s3zkiuCEkZrQKhphpoEGlsB
- Has to be the same configured in the Server, you can use one random generator to define your key [https://cloud.google.com/vpn/docs/how-to/generating-pre-shared-key].
- Expand the Advanced section.
- Enter the Phase1 Algorithms: aes128-sha1-modp2048!
- Enter the Phase2 Algorithms: aes128-sha1-modp2048!
- Click OK, then click Add to save the VPN connection information.
- Turn the VPN switch ON.
There are other sugestions for Phase1 and Phase2 Algorithms (steps 14 and 15):
Phase1: aes128-sha1-modp2048,3des-sha1-modp1024
Phase2: aes128-sha1,3des-md5
OR
Phase1: aes128-sha1-modp1024,3des-sha1-modp1024!
Phase2: aes128-sha1,3des-md5
If necessary, see more information about IPSec Negotiations in [https://www.watchguard.com/…/ipsec_vpn_negotiations_c.html].
Your VPN security will be defined by how strong are the User/Password, Pre-Shared Key and Phase1/2 Negotiations defined in your configuration. And of course, you have to find a balance between security and performance.
This tutorial works perfectly for the Quick VPN feature on D-Link devices, such as DIR-882 AC2600 [https://ca.dlink.com/…/dir-882-ac2600], by the way.