What is this?

This knowledgebase contains questions and answers about PRTG Network Monitor and network monitoring in general.

Learn more

PRTG Network Monitor

Intuitive to Use. Easy to manage.
More than 500,000 users rely on Paessler PRTG every day. Find out how you can reduce cost, increase QoS and ease planning, as well.

Free Download

Top Tags

View all Tags

ssl certificate sensor and firewall



Hello, We are trying to deploy a SSL certificate sensor and could not find any guide abut the necessary URL/Ports that needs to be open. Please advise. Thanks, Yaron

http-ssl-certificate-expiry ssl ssl-certificate

Created on Mar 9, 2020 1:24:38 PM

2 Replies



Hi there,

You need to make sure that the port for the web site is reachable, which is usually 443.

Kind regards,
Birk Guttmann, Tech Support Team

Created on Mar 9, 2020 5:03:00 PM by  Birk Guttmann [Paessler Support]



Thank you for your reply.

The probe can reach the monitored website (internal) but the probe has no internet access and its receiving the errors below:

Warning by lookup value 'No' in channel 'Root Authority Trusted' — Warning by lookup value 'Unable to check revocation status' in channel 'Revoked' (OK. Certificate Common Name: *.domain.com - Certificate Thumbprint: ---------------------------------------)

Please advise,

Created on Mar 12, 2020 8:44:15 PM

Last change on Mar 13, 2020 8:58:12 AM by  Birk Guttmann [Paessler Support]

Disclaimer: The information in the Paessler Knowledge Base comes without warranty of any kind. Use at your own risk. Before applying any instructions please exercise proper system administrator housekeeping. You must make sure that a proper backup of all your data is available.