Is Apple Remote Desktop VNC?

Don't install LanSchool on your mac server. Use ARD to view/control your server. Uninstall LanSchool and see if that clears up the issuse.

P.S. make sure you restart before trying again.

under sharing in system preferences, you have Remote Management checked? Make sure you have a local Admin account and then do the allow access for: Only these Users, and select your local admin account.

Then when you connect to that machine again in ARD, Control click it and put in the local admin username and password.

Johnny1600 wrote:

Don't install LanSchool on your mac server. Use ARD to view/control your server. Uninstall LanSchool and see if that clears up the issuse.

P.S. make sure you restart before trying again.

Hi Johnny,

I wrote a lot so sorry if I created confusion. Lanschool is installed on the student computers and not the server. It has been running on the snow leopard machines for two years without any problems, but I will go ahead and remove it as this is a reasonable test.

Johnny1600 wrote:

under sharing in system preferences, you have Remote Management checked? Make sure you have a local Admin account and then do the allow access for: Only these Users, and select your local admin account.

Then when you connect to that machine again in ARD, Control click it and put in the local admin username and password.

Remote management is definitely checked. The systems are clones of our existing systems with the only exception being that we migrated the apps and settings to Mountain Lion. There are two admin accounts [plus root] that are available to manage the system. Also, VNC used to work flawlessly and now actively refuses the connection. This is why I suspect something more than a simple configuration error.

When you cloned the units, did you make sure that your dhcp is not staticed?

Not exactly sure what you mean here.

If you mean DHCP is active and they are not using static IP's? then yes, I can see each machine in the main ARD screen and each one has a unique IP address.

If you ping them with the -a command from a pc do they come back with the correct name/ip address? Just to verify there isn't a DNS problem.

Are you managing these machines through Open Directory?

Sorry Yes I ment Static IP

1.Open Terminal and ssh to the system in question: ssh . Enter the admin password, and if prompted to accept the certificate, type YES then press Enter.
2.Type cd /Library/Prefrences and press Enter.
3.Type mv com.apple.ARDagent.plist com.apple.ARDagent.plist_bad and press Enter. Repeat this command with com.apple.RemoteDesktop.plist and com.apple.RemoteManagement.plist -- remember to add _bad to the end of each filename when moving it.
4.Type cd /Users/username/Library/Prefrences; replace username with the affected user's short username.
5.Type mv com.apple.internetconfig.plist com.apple.internetconfig.plist_bad. Repeat this step for com.apple.internetconfigpriv.plist and com.apple.remotedesktop.plist if they are present [remember to add the _bad bit to the filename].
6.If the end user is logged in, pick up the phone and call them, ask them in your nice admin voice to save their work and go get a cup of coffee. You will be force restarting the computer.
7.Once the user has saved his/her work, type sudo shutdown -r now and press Enter. Supply the password as needed for the admin account.
Wait two minutes for the remote system to restart, go back into Apple Remote Desktop, and rescan the IP address for the affected system. If you are still unable to remote control the system, go to the next, less secure method for correction.

Johnny1600 wrote:

If you ping them with the -a command from a pc do they come back with the correct name/ip address? Just to verify there isn't a DNS problem.

Are you managing these machines through Open Directory?

Sorry Yes I ment Static IP

No problem with DNS. We actually use Active Directory as the macs are only a tiny percentage of the installed computer base. I cannot VNC to the computer via IP address and I was able to add a computer to ARD via ip address, but not control it, although I can pull reports. The iMac I re-imaged as a test, that one I can remote control.

Try what I posted above to see if your ARD preferences didn't get hosed in the imaging process.

Johnny1600 wrote:

Try what I posted above to see if your ARD preferences didn't get hosed in the imaging process.

No dice. I'm going to put it aside for today and think overnight. If you have other ideas, please feel free to offer.

You could always move the ard agent on the client and name it .bad, then run update and it will re install the agent.

Let me know if this works. If not I will keeo researching it on my end. I am setting up more 10.8 machines and I can test this.

Johnny1600 wrote:

You could always move the ard agent on the client and name it .bad, then run update and it will re install the agent.

Okay, I have one machine working...for now at least.

I removed the ARD client and installed the working version from our Mac Server - goose egg. This is crazy, so I googled it and found this:

"I went to system preferences on my computers, to the sharing section of system preferences, unchecked remote management and checked screen sharing and remote desktop now seems to be working."

So I switched to screen sharing, then I was able to get a connection via VNC, although it froze after I logged in. So I rebooted and turned off screen sharing and turned on remote management - BOOM! I'm in.

Now I'm running updates and I'll try again. I will try this on a few others and post the results later today.

Son of a B! next machine that I imaged I switched to screen sharing only, connected via VNC and disconnected, now ARD is working on that unit. Next time I will not connect via VNC, simply enable screen sharing, switch back to remote management and then test ARD.

Okay, that is the official fix. Switch from remote management to screen sharing and back to remote management. That is all.

I looked around all over before finding this. Fixed it for me. Replaced Mac Mini with iMac at work using Setup Assistant to migrate the accounts/settings/data. Everything was flawless but it failed to let me connect. Tried as you suggested and all is right with the world. Thanks.

Richard Cranium's fix worked for me. I didn't even have to VNC into the box, I only had to uncheck "Remote Management", then check "Screen Sharing", then recheck "Remote Management" and it fixed it. Thank you everyone.