Sorry if this has been asked before. Half expecting som LMGTFY responses but looking for some human advice.

As in title, I have a closet with a ton of Cat6 ethernet runs that either go directly do devices or to Keystone jacks. I have a computer connected to one of those jacks with a 6 ft Ethernet cable. I would like to convert this computer to be my firewall/router. Is it ok to run that WAN connection through the existing keystone jack? Is this considered bad practice?

Im just hoping to get away with keeping this computer in the same physical location, thanks!