Anthony Ragusea

Q: cannot screen share to desktop, firewall not an issue

I've noticed that I can successfully connect my laptop to my desktop (both running Yosemite) via screen sharing while on my home network, but I cannot connect remotely.  I've turned off my firewall on both computers, but to no avail.  I get a "could not connect" error.  Doesn't matter what remote network I'm logged onto.  I should add that my home desktop is connected via an extended Airport Extreme to a hub Airport Extreme.  Cable modem.  I have checked both Airports and NTP mapping is enabled.  The problem is not with the computer at home falling asleep.  Settings in Sharing appear to be just fine--I have screen sharing enabled on both, Back to Mac is enabled on both.  As far as I can tell, everything is perfect.  Restarting of course has no effect.  Any ideas? I'm stumped. 

 

Thanks!

MacBook Pro (13-inch Late 2011), OS X Yosemite (10.10)

Posted on Feb 25, 2015 8:32 AM

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Q: cannot screen share to desktop, firewall not an issue

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  • by Linc Davis,

    Linc Davis Linc Davis Feb 25, 2015 9:25 AM in response to Anthony Ragusea
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    Feb 25, 2015 9:25 AM in response to Anthony Ragusea
  • by Anthony Ragusea,

    Anthony Ragusea Anthony Ragusea Feb 25, 2015 9:41 AM in response to Linc Davis
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    Feb 25, 2015 9:41 AM in response to Linc Davis

    Thanks Linc, I've already read that page and as far as I can tell all of that is taken care of.  The ports shouldn't be blocked with the firewall down, and everything is up to date firmware-wise.  Yes I'm using two routers, but the extended Airport Extreme is in bridge mode so there shouldn't be a multiple NAT conflict.  I'm not using the modem as a router. 

  • by Linc Davis,

    Linc Davis Linc Davis Feb 25, 2015 11:49 AM in response to Anthony Ragusea
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    Feb 25, 2015 11:49 AM in response to Anthony Ragusea

    What does this mean: "I have checked both Airports and NTP mapping is enabled."

  • by Anthony Ragusea,

    Anthony Ragusea Anthony Ragusea Feb 25, 2015 12:17 PM in response to Linc Davis
    Level 1 (5 points)
    Feb 25, 2015 12:17 PM in response to Linc Davis

    I'm sorry I had NTP on the brain--I mean NAT mapping is enabled.  Router mode is DHCP and NAT.

  • by Linc Davis,

    Linc Davis Linc Davis Feb 25, 2015 12:56 PM in response to Anthony Ragusea
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    Feb 25, 2015 12:56 PM in response to Anthony Ragusea

    There should be only one NAT router, not two. On that one, NAT-PMP must be enabled. Also, there can be no L2TP VPN endpoint on the network.

  • by Anthony Ragusea,

    Anthony Ragusea Anthony Ragusea Feb 25, 2015 1:06 PM in response to Linc Davis
    Level 1 (5 points)
    Feb 25, 2015 1:06 PM in response to Linc Davis

    Right, I read that about two NAT routers, but Apple's documentation says as long as one is in Bridge mode it should be ok.  I have no VPN running.  I don't see NAT-PMP as an option is Airport Utility--DHCP and NAT is what's currently selected, my only other options are DHCP Only and Off.  Could that be an issue?  I should add that all the devices we're talking about here are relatively older, at least 3-5 years old.  But I haven't read anywhere the Airport or the Mac must be relatively new to be able to do screen sharing. 

  • by Linc Davis,

    Linc Davis Linc Davis Feb 25, 2015 2:00 PM in response to Anthony Ragusea
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    Feb 25, 2015 2:00 PM in response to Anthony Ragusea

    I read that about two NAT routers, but Apple's documentation says as long as one is in Bridge mode it should be ok.

    NAT and bridge mode are mutually exclusive. If bridge mode is selected, it's not NAT.

    I don't see NAT-PMP as an option is Airport Utility

    The instructions for enabling it are linked to the support article above. If you don't have that option, your AEBS is too old and BTMM won't work. There is no way of getting it to work without NAT-PMP.

  • by Anthony Ragusea,

    Anthony Ragusea Anthony Ragusea Feb 25, 2015 2:07 PM in response to Linc Davis
    Level 1 (5 points)
    Feb 25, 2015 2:07 PM in response to Linc Davis

    Ah, see I didn't read anywhere that NAT-PMP was a relatively recent option in Airport.  That may be the cause of my problem because that's not an option for me in Airport Utility.  Thanks.

  • by Anthony Ragusea,

    Anthony Ragusea Anthony Ragusea Mar 3, 2015 6:34 AM in response to Anthony Ragusea
    Level 1 (5 points)
    Mar 3, 2015 6:34 AM in response to Anthony Ragusea

    No--as it turns out that's NOT the problem--I got a used 5th gen Airport and I still can't connect.  In fact, it's now worse--whereas before I could see my home computer under "Sharing" in my Finder, I just couldn't connect to it, now it's not even showing up as a shared computer.  Doing more reading, I don't think NAT-PMP is ever an option you can choose, DHCP and NAT is the correct choice according to Apple.  So maybe the problem ISN'T that my Airport was too old before, maybe it's something else...

  • by VikingOSX,

    VikingOSX VikingOSX Mar 3, 2015 7:05 AM in response to Anthony Ragusea
    Level 7 (20,606 points)
    Mac OS X
    Mar 3, 2015 7:05 AM in response to Anthony Ragusea

    NAT PMP is a selectable option on the Network panel under Network Options. I have a 4th gen AEBS and it is there in firmware version 7.6.4.

  • by Anthony Ragusea,

    Anthony Ragusea Anthony Ragusea Mar 3, 2015 8:03 AM in response to VikingOSX
    Level 1 (5 points)
    Mar 3, 2015 8:03 AM in response to VikingOSX

    Right, yes, I have that option as well and it's selected.  I though he was referring to a "Router Mode" called NAT PMP.  So that's not the problem.  My firmware is all up to date.  I'm seriously out of ideas here. 

  • by Anthony Ragusea,

    Anthony Ragusea Anthony Ragusea Mar 3, 2015 11:53 AM in response to Anthony Ragusea
    Level 1 (5 points)
    Mar 3, 2015 11:53 AM in response to Anthony Ragusea

    I should add that I'm now trying to go about this from a different direction--I'm trying to setup a global IP using NOIP which as far as I can tell I've done successfully.  Ping tests show the right global IP, it looks good using Airport Utility, yet when do a port check none of the ports can be seen--I get a "no route to host" error.  No idea what the problem is.