Intermittent Connectivity Issue with Specific Website on Company Network

[Tym1]

I am experiencing a rather peculiar and intermittent issue when trying to access a specific website from within my company's network. The problem manifests inconsistently: at times, my requests to the website are successful, and I receive the expected responses. However, at other times, while the network traffic appears to pass through, there is no response from the website.

A few details to note:

The access to this site has been authorized in our network settings.
This issue does not occur when I attempt to access the site from my phone or when connected to a network outside of my company.
I have checked the Fortinet firewall logs; sometimes they show a response, and other times they do not, without any clear pattern.
I've already tried the following:

Ensuring that firewall settings are not blocking the site.
Checking for any specific error messages or patterns in the network logs.
Attempting to access the site from different devices within the company network.
Despite these efforts, the problem persists. The intermittent nature of this issue is particularly baffling. I am looking for suggestions or insights that might help in diagnosing and resolving this issue. Has anyone else experienced something similar or can offer any advice?

Thank you in advance for your assistance.

[smaruvala]

Hi,

- Is there any difference in the Policy or NAT or route the traffic takes in working and non-working situations?

- In a non-working scenario do you see the return packet? Or is the return packet count is zero?

- Was this working fine before and stopped working suddenly or was it never tested before?

- Have you tried to take any packet capture in the client or the firewall to see a difference in working and non-working scenarios? If the issue is intermittent and not reproducible easily then it will be difficult to take this.

- Do you have any devices after the firewall? 

Regards,

Shiva

[Tym1]

Hello Shiva,

Thank you for your response and the insightful questions.

1. Regarding the difference in policy, NAT, or traffic route in working vs. non-working situations, there is no noticeable difference in the configurations or policies between these scenarios.

2. In the non-working scenario, the return packet count is zero, indicating a lack of response in these instances.

3. The access to the website was functioning correctly before and suddenly stopped working. It wasn't a gradual change but a sudden stop in functionality.

4. There are no additional devices after the firewall in our network setup.

5. We have a dual internet connection setup, and I suspect that the issue might be related to the round-robin configuration. We are considering directing the traffic for this specific link through a single address to see if it resolves the issue.

Thank you again for your help and suggestions. Your input is greatly appreciated as we work to resolve this issue.

Best regards,