bonjourNetworkservices
While browsing for services in my local network with Bonjour, I notice that my MacBook Pro provides the _atc._tcp. service. However I couldn't find a description for such a service from the canonical list of macOS services nor inside the DNS-SD registry.
The question is, what is that service? How to use it?
It looks like you want something like NetSpy or ActyMac to monitor employee activity. It will handle what you want and more, although I'm not sure I would suggest the orwelian approach to employee management.
You may want to look into a pure network monitoring tool like Paessler.
The easiest solution would be for you to just monitor the server log on your OS X server for the time the user logs-in and logs out. A simple script that tracks the time and totals them into a spreadsheet using a nightly cron job.
You can also just use the last command as seen in the screenshot aslong as the file has not be cleared.
You may want to try other basic unix system logging scripts.
This is a partial answer, but it perhaps contains valuable information to whoever is reading this.
As I was able to add an 'Internet account' from inside the LAN, I decided to set Wireshark to work and try to figure out the port that way. I found out that the initial authentication and selection of services is done via port 443.
After forwarding port 443, I was able to add the internet account from outside the network. This pretty much answers the question, but does not resolve the issue for the full 100% yet, so I figured I'd still keep this open for a bit.
At this point I'm stuck at creating an agenda in the iCal account, however, running into a rather generic error message:
This is a work in progress, and any pointers on that error are appreciated.
EDIT: Further network sniffing let to no more information. Once logged in, the rest of the traffic is conducted over port 8443, which is duly forwarded. However, it still won't work outside the network. The fact that it does not work via VPN as well strikes me as odd, and makes me suspect a different issue than the TCP layer.
Best Answer
The
_atc._tcp.service is/was the Shared iTunes Library service.I'm out and about at the moment, but when I get a chance I will update this answer with some sort of link/source to back this up.
[EDIT]
I haven't yet had a chance to have a thorough look for a source, although I did do a quick Google search and found a reference to the
_atc._tcp.service at this MacRumors discussion. In it you'll see the 10th comment (by priitv8) states:Also, it occurred to me that you may want to download Bonjour Browser and see if that sheds any more light on this for you. It's an old app but works well (although I haven't used it in macOS Sierra - not sure what you're using).
As an aside, the list of Bonjour service types used in Mac OS X you linked to is not an exhaustive list. It was only a list of common Bonjour service types used in Mac OS X and hasn't been updated since July 2004.