Hi @Vishal, upgrading the Duo Authentication Proxy should be pretty seamless, as the installer preserves your current configuration and log files when upgrading to the latest release. You can make a backup copy before running the upgrade just to be safe, which is always a good idea. You’ll find instructions on how to do that, including the directories you’ll need, both in our docs on how to upgrade the proxy as well as this help article. I hope that helps! 
Hi @Vishal
Unfortunately, we can’t know this without seeing your exact configuration. Newer releases of the Authentication Proxy do stricter checking on options, so it is possible that you could have something in your config today that is invalid or incorrect that the config checker in the current release would flag that would prevent startup. If this is the case, it will tell you before you install the upgrade. Friendly reminder that the community is NOT the correct place to share your config files, and you should contact Duo Support instead. 
No, it should have no impact provided the Authentication Proxy starts and the config is valid.
Definitely create a backup copy of the authproxy.cfg and any certificate+key files in the configuration directory. You may want to test the upgrade on a non-production server first in case any issues do crop up. Also, you can always reinstall the previous version of the Authentication Proxy in the event there is an issue, until you are able to troubleshoot it further and correct it.
If you’re really concerned though, it might be a good idea to open a Duo Support case to review your configuration with them prior to making any changes. They will be able to identify and correct any issues ahead of time, and if you do run into problems still, they can also assist with those!
