NEIKEv2Provider wants to sign using key “Norton” in your keychain

You're getting scammed. There is no reason to ever install or run any 3rd party "cleaning", "optimizing", "speed-up", anti-virus, VPN or security apps on your Mac.  This documents describe what you need to know and do in order to protect your Mac: Effective defenses against malware and other threats - Apple Community and Recognize and avoid phishing messages, phony support calls, and other scams - Apple Support.  

There are no known viruses, i.e. self propagating, for Macs.  There are, however, adware and malware which require the user to install although unwittingly most of the time thru sneaky links, etc.   

Anti Virus developers try to group all types as viruses into their ad campaigns of fear.  They do a poor job of the detecting and isolating the adware and malware.  Since there are no viruses these apps use up a lot of system resources searching for what is non-existent and adversely affect system and app performance.

There is one app, Malwarebytes, which was developed by a long time contributor to these forums and a highly respected member of the computer security community, that is designed solely to seek out adware and known malware and remove it.  The free version is more than adequate for most users.  

Also, unless you're using a true VPN tunnel, such as between you and your employer, school or bank's servers, they are useless from a privacy standpoint.  Read these two articles: Public VPN's are anything but private and Former Malware Distributor Kape Technologies Now Owns ExpressVPN, CyberGhost, Private Internet Access, Zenmate, and a Collection of VPN “Review” Websites. 

Sounds like you've may have adware on your Mac. Download and run the free versions of download and run the free version of Malwarebytes.

suzimatt wrote:

Thank you for this. I use Norton 360 but uninstalled it when this happened. Now I have no anti-virus program on my Mac. I think this happened when I updated the Mac to the latest OS.

Some part of Norton apparently didn’t get uninstalled.

Some remnant is trying to establish what is likely a first-few-hops VPN connection.

Which you don’t need.

Most add-on security apps tend to insinuate themselves into macOS not unlike actual malware does, and various vendors have the occasional issue with incomplete app removal or with persistent app-generated corruptions. Some vendors are better than others.

Check with Norton support. Some add-on security vendors use a separately-downloaded app removal tool, for instance.

suzimatt wrote:

Thank you for this. I use Norton 360 but uninstalled it when this happened. Now I have no anti-virus program on my Mac.

As I said earlier you don't need an A/V app. They only interfere with the system and applications performance