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FIrefox (Error code: ssl_error_weak_server_ephemeral_dh_key)

Occasional Contributor

FIrefox (Error code: ssl_error_weak_server_ephemeral_dh_key)

Using SDN Controller v2.5.15.1175


Getting this error message after upgrading to the latest Firefox version 39.0.


SSL received a weak ephemeral Diffie-Hellman key in Server Key Exchange handshake message.

(Error code: ssl_error_weak_server_ephemeral_dh_key)


IE and Chrome seem to be working.


A workaround to allow weak cyphers in Firefox seems to work:

1) In FireFox, enter "about:config" in the URL field and press enter.

2) Accept the "This might void your warranty!" warning :)

3) In the search field at the top, enter "security.ssl3.dhe_rsa_aes"

4) Double click each result (128 and 256) to toggle the Value to "false"


Is there a way to fix this with keytool to gen a new cert?




Frequent Advisor

Re: FIrefox (Error code: ssl_error_weak_server_ephemeral_dh_key)



Thank you for contacting the HP SDN Forum. At the moment I am researching your issue with our engineering department to see if they can upgrade the script. I will get back to you once I get an official notice that the script has been updated.


Best Regards,



CoE/SDN Team

New Member

Re: FIrefox (Error code: ssl_error_weak_server_ephemeral_dh_key)

was able to generate a new cert but i cant login to the web page, now on firefox it says:

"Unable to connect

Firefox can't establish a connection to the server at

The site could be temporarily unavailable or too busy. Try again in a few moments.
If you are unable to load any pages, check your computer's network connection.
If your computer or network is protected by a firewall or proxy, make sure that Firefox is permitted to access the Web."

But from chrome it states:

"This webpage is not available







Occasional Advisor

Re: FIrefox (Error code: ssl_error_weak_server_ephemeral_dh_key)

any update on this issue? why is this listed in 'resolved issues' tag? thanks.


Re: FIrefox (Error code: ssl_error_weak_server_ephemeral_dh_key)

Please use version 2.7.10 or newer of the VAN SDN Controller.  There is an OVA download package, or debian package with upgrade instructions. Download link below:

Best Regards,


Scott Koster | Technical Marketing Engineer
HPE Aruba