Yealink Phone Fail to connect to OpenVPN

Fail to connect to OpenVPN.

Symptoms

1. No VPN icon on the screen with the VPN file imported and the phone rebooted

2. No response with the VPN file imported

3. VPN will not reconnect after disconnection

4. Fail to use the OpenVPN with two-way SSL authentication

Relevant Error Report

Resolution

1. Upgrade the phone to the latest firmware on the website: https://support.yealink.com/en/portal/home

2. Follow the guide OpenVPN Set-up guide to check the configuration file vpn.cnf:

• Check the VPN server’s IP address: remote 10.88.0.107 #VPN server’s IP address.

• Check the names of the VPN files: vpn.cnf, ca.crt, client.crt, client.key and their route /config/openvpn/keys/xx.xxx (page 15).

• Align the compression setting comp-lzo for server and client. (If the server side enables comp-lzo, the client side should enable it).

• Vpn.tar file for the phone should include: vpn.cnf, keys folder including ca.crt, client.crt and client.key. (page 17).

• Importing the VPN files in the web user interface, go to Network > Advanced > VPN.
  

3. Confirm the VPN has been enabled from one of the following methods:

• On the web user interface, go to Settings > Advanced Settings > Network > VPN > VPN Active > On.

• On the web user interface, go to Network > Advanced > VPN > Active > On (Mode: OpenVPN, if any).

• Provisioning parameter: network.vpn_enable = 1

4. Check if the signature algorithm of the client certificate is supported by the phone. Old models before V80 firmware support MD5 and SHA1 signature algorithms.
   Double-click the client certificate file to check the validity time and signature algorithm of the certificate.
   

5. As the certificate cannot be verified if the time is incorrect, make sure the phone syncs with the NTP server correctly.

6. If you are using two-way SSL authentication, please disable it via Security > Trusted Certificates > Only Accept Trusted Certificates on the web user interface.
   If the VPN is OK afterward, please check from the certificate side.

7. If the issue persists, please follow the guide and reproduce the issue to capture the level 6 log for us to analyze:

1. On the web user interface, go to Settings > Configuration to select local log/module log to level 6.

2. Reboot the phone.

3. After the phone boot up to an idle screen, wait for 20 seconds.

4. Export the log file.

5. Raise a ticket with the logs at https://ticket.yealink.com/.

6.