Partner could not be contacted at given network address

[dthndmills]

I've been using TeamViewer for years and it has worked great. However, two days ago I could no longer connect with my other computer. When I try to connect I get the following message - "A connection could not be established. Partner could not be contacted at the given network address." The computer I am connecting to is up and running ok and internet connection is good.
Any help will be greatly appreciated.

What is odd though, this morning I took my laptop to where the computer is that I log on too and when I tried to connect to it, it connected ok. As of right now it seems to be from my home that I am having the problem.

[tgil723]

The same thing is happening with me. TeamViewer worked great over the weekend (as it has for the past few years) but when I tried it on Tuesday it wouldn't connect. Even machines on my own network aren't accessible. I'm a Comcast user and am wondering if they started blocking it for some reason.

[jasonwmartin]

Same thing here...can't connect to any of my partners that I have been able to for months.  Opened a ticket w/TeamViewer yesterday, still no response from them!

[jasonwmartin]

FYI...it's Comcast! 

I just connected to personal hotspot on my Verizon iphone & it worked.  I also noticed I could connect to my partners (customers) who have Comcast business.  So it appears the issue is Comcast is blocking port 5938 for home users.

[jasonwmartin]

Actually, it's Comcast & TeamViewer...seems Comcast must have updated their networks/routers to use IPv6.  I disabled IPv6 on my router (I have a personal router/wireless/VPN device - not using just the cablemodem for protection!) and TeamViewer works!

TeamViewer appears to not support IPv6...maybe that's coming in a future release.

Hope this helps someone!

[EorEquis]

I don't think IPv6 is the issue.  Downgrading both partner machines to TV v10 lets them connect again...seems unlikely the older version would 'support IPv6" but 11 would not.

[jasonwmartin]

I agree with you if downgrading both to v10 also resolves the issue that it's unlikely the older version would "support IPv6" where 11 would not.

But I disagree with you that it's not IPv6.  I disabled, it worked, I re-enabled & it didn't.  I did this several times in a row to be absolutely sure and each time I re-enabled IPv6 it stopped working and each time I disabled IPv6 it worked fine on v11.

It could be v10 & v11 both do support IPv6 but the actual TV server(s) that v11 is served from (from my logs it says 'server25303.teamviewer.com') has IPv6 turned off on the NIC whereas the server(s) v10 is served from has it turned on...who knows except someone @ TV which I still haven't received any response from my support ticket yesterday.

Did you try disabling IPv6?  If not, maybe there are 2 options to resolve this issue: 1) disable IPv6 or 2) remove v11 & install v10.

[EorEquis]

Hrm....curiouser and curiouser actually.

• No, I didn't disable IPv6 yet...haven't dug around enough on Comcast's modem/router to see where just yet.
• I'm currently playing around with changing networks, and have noticed something interesting.  It appears (I'm testing all the possible combinations to be sure) that only the *destination* computer has to be off of Comcast's network.  I just connected to a remote system on both my phone's hotspot and the Xfinity hotspot (see below) from my machine on the xfinity/comcast home wifi
• The fact I can connect to a destination computer using the xfinity open hotspot *running from the same modem*...so long as it's not on my in-home wireless....is interesting.  It seems to suggest it's not "comcast" so much as something they've pushed to their modems related to the modem's in-home wifi config
  

I'm about to do some more digging, maybe disable the comcast firewall completely for a moment, see what I can sort out.

[EorEquis]

Ok, first things first : You're obviously right, it's somehow IPv6 related (no matter how little sense that makes....maybe v10 just didn't even try to use IPv6 before?).  Wound up just disabling IPv6 on each machine, and it connects right up again.  (There's no way to disable it on the Comcast modem, so sayeth their support docs, and I didn't feel like arguing with the modem to see if they were right)

So...short term, problem is worked around by simply disabling IPv6, as you said.

Now...in the context of "What the hell is actually going on?", did some other testing as well, and it's just...really weird.  There seems to be NO rhyme or reason to what combination of "on network" vs "on hotspot" works, other than if both machines are on the Comcast/Xfinity home network provided by their modem...it doesn't work.  Everything below was done with IPv6 still enabled.

With 4 different computers, using Phone Hotspot (PH), XFinity Hotspot (XH), and XFinity Home Network (XHN) :

• #1 on XHN could connect to #2 if #2 was on PH or XH, but not if #2 is on XHN
• #2 on XH or PH could connect to #2 on XHN
• Nothing could connect to #3 if #3 was on XHN...but if #3 was on XH or PH, #1 and #2 could connect, *regardless of their network*
• #4 can't connect to anything at all if ANY X is involved.  Put #4 on PH and any other computer on XH or XHN...nothing.  Put #4 on XH, any other computer on PH, nothing.  Put both computers on PH...works like a charm.
  
• Now it gets REALLY weird...the android client could connect to anything not on XHN (even #4 on XH) so long as the phone is on 4G.  Put the phone on XHN, and it can't connect to anything on XHN, but could connect to anything on XH or PH
• Disabling both Windows Firewall and Comcast's firewall at the modem had no effect

[mflenniken]

Having the same problem. I disabled IPv6 on my AT&T Motorola router and all systems now work. Thanks.

[paleGreen1]

I was having the same problem since yesterday and pulling my hair out trying to fix it.

I don't think I can disable IPv6 on my U-verse router, so I just disabled it on my Windows 7 network connection and BAM!  I can connect again!

Fyi, I also noticed that TeamViewer automatically updated itself two days ago.  It sounds like this latest version is now using IPv6, but it's failing for some reason.  I'm going to keep IPv6 disabled for the foreseeable future.  Hopefully TeamViewer will have the kinks worked out by the time I need it (if I ever do).

Thank you to everyone on this thread for saving what's left of my hair!! 

[megamoto]

I can confirm that disabling IPv6 on my local workstations fixed this issue as well.

Start-> Control Panel -> Network and Sharing Center -> Change Adapter settings -> right-click on network adapter, select Properties -> uncheck IPv6 checkbox -> click OK.

Worth noting is that Comcast recently replaced my router so that is in line with the previous comments.

[dthndmills]

So let me get this straight since I started this thread. Can I disable the IPv6 on my laptop or on the router?

[EorEquis]

So let me get this straight since I started this thread. Can I disable the IPv6 on my laptop or on the router?

Either should work.

[dthndmills]

I made the necessary changes and it worked- GREAT!!   Thanks