Cannot connect iMac display to Apple TV

iW00 wrote:

If you haven't tried this yet, I would suggest with cycling power on all of your devices which are involve in this setup, starting with your Router, Airport Extreme, iMac and Apple TV.

If your Airport Extreme is setup in Bridge Mode, then your Router is the device that distributes settings, not Airport Extreme. In your notes, you haven't mention if Router was switched OFF and ON again.

The Airport Extreme is the router! (And it is in Bridge mode.)

Power cycling all the devices -- Airport Extreme, iMac, and Apple TV is of course one of the very first troubleshooting steps I took.

John Galt wrote:

Uninstall Intego. It may not be direct cause of the problem but your Mac cannot operate properly with it installed.

To uninstall it you must use Intego's uninstallation utility included with its downloaded installation package. Do not download, install, or use any other utility or technique to eradicate it.

Once uninstalled, restart your iMac, your Extreme, and the Apple TV. Then, review the following Support documents:

Apple TV: Basic troubleshooting - Apple Support

Use AirPlay to see your Mac screen on an HDTV - Apple Support

For specific help with iTunes Home Sharing, read Use Home Sharing to share iTunes content with other devices on your home network - Apple Support

Apple TV is connected via Wi-fi to the same LAN,

Video is a bandwidth-intensive process for which a wired connection would be preferable, but if that is not possible make sure the AppleTV is in a location such that it is able to reliably communicate with the Extreme. You may need to experiment to determine each one's optimal location.

I'm skeptical about your advice on Intego, although I may still try it. Note that I already tried disabling the Intego NetBarrier firewall.

The 2nd doc you site is, alas, of no help: as I said, I do see the AirPlay icon in my iMac's menu bar, and I do see my Apple TV listed there. (And as I said further, I can successfully ping the Apple TV from my iMac.)

The 1st doc contains all the general types of troubleshooting that, of course, I already tried. That's why I wrote to this forum -- because the usual things did not work.

John Galt wrote:

...A

pple TV is connected via Wi-fi to the same LAN

Video is a bandwidth-intensive process for which a wired connection would be preferable, but if that is not possible make sure the AppleTV is in a location such that it is able to reliably communicate with the Extreme. You may need to experiment to determine each one's optimal location.

Yes, definitely the Apple TV is connected via wi-fi to the same LAN to which my iMac is connected via Ethernet. I said that in my original post.

Given that the other iMac I mention can mirror its desktop on the Apple TV and that that iMac connects to the LAN via wi-fi (whereas the troublesome iMac is connected via Ethernet), bandwidth is not at all indicated as the problem.

Moreover, the Apple TV is closer to the Airport Extreme by some 20 feet, but in the same direction, as the more distant wi-fi connected iMac that does mirror to the Apple TV. And the Apple TV has no difficultly whatsoever streaming material via its own apps, so it's getting the wi-fi signal just fine.

thanks for the suggestions, though.

John Galt wrote:

murrayE wrote:

I'm skeptical about your advice on Intego,

Then I am skeptical about your willingness to solve your problem. Good luck.

Sorry -- no intention to offend! I meant solely that it was unclear what uninstalling the Intego software would achieve given that it already has the built-in capability to disable its firewall. I do like to have a good rationale for making changes when troubleshooting.

So please tell me: is there something particular you know about the Intego software, e.g., substituting some device driver of its own in place of an OS X driver? Or about some ports that Intego blocks even when you disable its firewall?

Also, in another thread on this forum, there seem to be a significant number of folks who experienced the same problem as I have once they upgraded to Yosemite. (I didn't have the Apple TV before I upgraded to Yosemite, so I cannot tell whether I'm in that situation.)

iW00 wrote:

murrayE wrote:

The Airport Extreme is the router! (And it is in Bridge mode.)

You are wrong! If your Airport Extreme is set to Bridge Mode, then that means some other device is using DHCP and NAT to provide IP addresses to devices on your network. What is your Airport Extreme connected to? If you have a Router provided by your ISP that your Airport Extreme is connected to, then that device is using DHCP and NAT and all your devices on your network are getting IP addresses from it.

Wi-Fi base stations: Extending the range of your wireless network by adding additional Wi-Fi base stations - Apple Suppo…

http://www.apple.com/shop/question/answers/readonly/what-is-the-difference-betwe en-bridge-mode-and-not-bridgemode/Q24KPT…

murrayE wrote:

Power cycling all the devices -- Airport Extreme, iMac, and Apple TV is of course one of the very first troubleshooting steps I took.

So, did you Cycle power on the device that your Airport Extreme is connected to as I suggested? That would be a first step which I would do before removing any software from Mac.

If other devices works as should, then there is no issue with an Apple TV. Issue is either with network setup/settings or some Software on your Mac causing issue.

If above step wouldn't resolve this problem then as John Galt suggested, I would uninstall the software which possibly has some impact. Any built-in and 3rd party security apps will be a first to blame...

According to AirPort Utility, the Airport Extreme's Network tab shows Router Mode: Off (Bridge Mode). However, the Airport Extreme is cabled from its Ethernet WAN port to the Ethernet/LAN port on an Arris TM822 cable modem. The Arris is just a cable modem and is not a cable modem-router combo.

The Ethernet hard-wired connection from the Airport Extreme to my iMac works normally, as does the wi-fi connection from it to the 2nd iMac. And the Apple TV can, via Airplay, mirror the desktop on the 2nd, wi-fi-connected iMac (as well as stream content through its native apps).

That's what suggests the fault with Apple TV mirroring of the first iMac is something about that iMac. Note that in a different thread on this forum, a number of users have reported similar Airplay mirroring-to-Apple TV issues when they updated to Yosemite. My 2nd iMac, which mirrors OK, is still running Mavericks.

John Galt wrote:

Uninstall Intego. It may not be direct cause of the problem but your Mac cannot operate properly with it installed.

To uninstall it you must use Intego's uninstallation utility included with its downloaded installation package. Do not download, install, or use any other utility or technique to eradicate it.

Once uninstalled, restart your iMac, your Extreme, and the Apple TV. Then, review the following Support documents....:

OK, completely uninstalled Intego Internet Security X8 (NetBarrier and VirusBarrier). Power cycled Airport Extreme, restarted iMac, power cycled Apple TV.

No change in behavior: still when I try to mirror the iMac on Apple TV, in the AirPlay drop-down form the Mac's menu bar I do see my Apple TV listed as available to connect to, but when I click on that, after a delay I get a pop-up window "Could not connect to Apple TV." And yet still can successfully ping the Apple TV from the iMac!

iW00 wrote:

murrayE wrote:

The Airport Extreme is the router! (And it is in Bridge mode.)

You are wrong! If your Airport Extreme is set to Bridge Mode, then that means some other device is using DHCP and NAT to provide IP addresses to devices on your network. What is your Airport Extreme connected to? If you have a Router provided by your ISP that your Airport Extreme is connected to, then that device is using DHCP and NAT and all your devices on your network are getting IP addresses from it.

Wi-Fi base stations: Extending the range of your wireless network by adding additional Wi-Fi base stations - Apple Suppo…

http://www.apple.com/shop/question/answers/readonly/what-is-the-difference-betwe en-bridge-mode-and-not-bridgemode/Q24KPT…

murrayE wrote:

Power cycling all the devices -- Airport Extreme, iMac, and Apple TV is of course one of the very first troubleshooting steps I took.

So, did you Cycle power on the device that your Airport Extreme is connected to as I suggested? That would be a first step which I would do before removing any software from Mac.

If other devices works as should, then there is no issue with an Apple TV. Issue is either with network setup/settings or some Software on your Mac causing issue.

If above step wouldn't resolve this problem then as John Galt suggested, I would uninstall the software which possibly has some impact. Any built-in and 3rd party security apps will be a first to blame...

You are of course correct: I just realized that the actual router is a Netgear router whose wi-fi is used only to go to a home security system. The cable modem's goes by Ethernet to the Netgear, then the Netgear goes by Ethernet to the Airport Extreme, which is set in Bridge Mode.

AirPort Utility lists the Apple TV (on wi-fi) as a client of the Airport Extreme. My iMac is an Ethernet-connected client of the Airport Extreme.

Anyway, power recycling all these devices, including the Netgear router, produces no changes -- still cannot mirror the iMac to the Apple TV.

(Given that the 2nd iMac, which is on wi-fi, does mirror to the Apple TV and always has, I'm not surprised that the power cycling has produced no changes.)

John Galt wrote:

Uninstall Intego. It may not be direct cause of the problem but your Mac cannot operate properly with it installed.

To uninstall it you must use Intego's uninstallation utility included with its downloaded installation package. Do not download, install, or use any other utility or technique to eradicate it.

Once uninstalled, restart your iMac, your Extreme, and the Apple TV. Then, review the following Support documents....

I should add that the 2nd iMac -- the one connected to the LAN by wi-fi -- also runs Intego Internet Security X8, and that one can be mirrored by Airplay to the Apple TV. Moreover, the Intego software has never caused any kind of problem on either that iMac or my own iMac (the one that's Ethernet wired to the LAN).

That 2nd iMac runs Mavericks, while my own runs Yosemite. So my conclusion at this point is either there's some bug in Yosemite or else some other software on my iMac that's blocking Airplay mirroring connection (yet does not disallow pinging to the Apple TV!).