ssl certificate expired before date of expiration?

Hello All,
I have installed SSL certificate on one of the site on server two months ago.The validity period of certificate is one year,which is still remaining.
When I accessed my web page it gave me warning that ip address dosen't match the site's ip address when certificate was installed.I understood this error ,as I recently changed the ip address of the server,where the site is hosted.So it is giving error that certificate is expired.
But I don't know whta to do for this?How should I reinstall certificate aggain?Or It will be enough if I generate keys?How should I go for this as I completely forgot what I did when I installed certificate.
Can anybody give me help to solve issue.
THank you

 

 

 

 

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