Peer certificate CN did not match expected CN


We have multiple servers that communicate with each other. This has worked without issues for years.

A few days ago, a request between the servers failed. The error:
file_get_contents(): Peer certificate CN=*' did not match expected'

The error only pops up rarely, a few times per week. All the other requests (which are exactly the same) work fine. We use Plesk for managing the server.

My hosting provider is: OVH

I already did a google search, and found another website having the same issue:

I'm not sure if this is the right place to ask. But I'm a bit confused about this error. Did the request between my servers somehow got redirected to another server with the wrong certificate? I didn't make any DNS changes...

do your server manage too? it goes to a parking page so it's unlikely but looks like your server failed to parse or send SAN at tls handshake



No we don't manage nor do we know where that domain name came from... :worried:

We did have some performance issues on our server the last few days. Nginx reaching max_children. We've increased that setting.

I personally don't think this be debugable, but better retry connection. I would not be surprised if it was cosmic ray hitting Lan cable flipping a bit in transaction


Not the best place to ask. Seems more a DNS problem or something odd in php error handling. Might even ask OVH how to check DNS.

To debug you could replace the file_get_contents with php curl_exec. That would allow you to see the response headers and other details possibly. See php programming forum for details (even stackoverflow). Not sure this would help but it might.


Thank you all for the responses :slight_smile:

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Probably a firewall of some kind.

If you tell us the actual domain name, we might be able to be more helpful.


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