ในกรณีต่ออายุ license plesk แล้วไม่สามารถ activate ต่ออายุได้ ลองเช็คดังนี้ครับ
https://support.plesk.com/hc/en-us/articles/213383529Symptoms
The product license fails to update. The following errors may occur:
PLESK_ERROR: Licensing Server Unreachable: Unable to connect with licensing server.
Please make sure that your network allows communication to ka.plesk.com:5224.
For more details check system help pages.
or
PLESK_ERROR: Couldn't resolve host name
or
PLESK_ERROR: Can't connect to ka.plesk.com:5224 (Timeout)
Plesk is not accessible:
PLESK_ERROR: Error: The license key is invalid. in order to use Plesk, please obtain and install a new valid license key.
Your license key has expired. To continue using your Plesk, you must purchase a non-expiring commercial license key.
Cause
Plesk tries to connect to the license server ka.plesk.com on TCP port 5224 to update the license, but cannot establish connection.
Resolution
Since February 5, 2018 , ka.plesk.com hostname will be resolved into 3 different IP addresses based on round-robin logic:
195.214.233.80 (old one)
195.214.233.81 ( new )
195.214.233.82 ( new )
Additionally, since the same date, the Key Administrator will accept connections from Plesk on two ports :
5224 (old one, non-standard port)
443 (new, the default HTTPS port)
Make sure that Plesk is able to establish connection to all three Key Administrator IP addresses and both Key Administrator ports in all their combinations (see the table below):
IP Port
195.214.233.80 5224
195.214.233.80 443
195.214.233.81 5224
195.214.233.81 443
195.214.233.82 5224
195.214.233.82 443
For example:
# ping ka.plesk.com
# telnet ka.plesk.com 5224
If the license server does not resolve into the correct IPs, check the /etc/hosts file.
In case any of these servers are behind a firewall and old IP addresses of Key Administrator are listed in the firewall rules, please add new IP addresses of the Key Administrator to the firewall rules before February 1, 2018 to allow your servers to connect to ka.plesk.com . This can be checked with these commands, depending on your OS:
Linux:
# nmap -P0 -p5224 ka.plesk.com
# telnet ka.plesk.com 5224
# traceroute ka.plesk.com
Windows:
telnet ka.plesk.com 5224
tracert ka.plesk.com
Note: Telnet client should be installed additionally for Windows -> how to install Telnet client
If APF firewall is used, check /etc/apf/allow_hosts.rules for the mentioned IPs or the hostname ka.plesk.com