Local Network Operation

[davefaz]

I have a few computers at home, and I would like to enable Teamviewer for local network only. The reason for this is that one of the computers is actually connected to a VPN, which significantly slows Teamviewer because it is going through the remote VPN server. I think I would get far better performance if the computers were just talking locally.

Reading a FAQ in the Teamviewer support area, it seems that I need to set "Incoming LAN connections" to "accept exclusively". I have experimented with this setting and it really does work. Everything seems as normal, but the connection is much faster.

However, there is a warning in the support area that doing this, firewall software may "open an acceptance dialog". And indeed when I enable it a small security warning graphics appears. The problem is that I don't know what this means and what the risks are. Basically speaking I do not mind if local LAN security is compromised because I don't have any security on the network anyway. But of course I do mind if I am exposed on the WEB. Can someone tell me what this statement means and whether or not I am safe using this option?

[matt]

What is the EXACT wording of the dialog that is opened?
What program generates the dialog? Windows Firewall?

[davefaz]

Hello, and thank you for replying.

When you configure Teamviewer ( Extras, Options, Accept Incoming Lan Connections = Exclusively ) a small orange security symbol appears on the Teamviewer configuration page next to the option you selected. I assume this is a warning that is further explained on this page -

http://www.teamviewer.com/en/help/40-Can-TeamViewer-be-used-within-a-local-network-LAN-only.aspx

The important text on that page is - "By default this feature is deactivated because software firewalls may open an acceptance dialog when configured this way".

Now the problem is that I don't know what that means and what the full risks are. Any threats would be from the WAN connection that exists on the Local Network which is through a router - which in turn of course has it's own firewall. My question it, is that security issue a problem in my specific case?

[matt]

I think (Note: my personal opinion) is that this warning is saying that (say) Windows Firewall may ASK you if it is OK to allow these connections.

I you have control of the local network, I see no security issues in allowing this, other than existing security issues that you may have.
I don't think that you are adding any NEW security issues by allowing this