"Use alternate DNS support"

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troymurray

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Post by troymurray » Thu Nov 06, 2008 3:33 am
James,

First off, I want to state that I love, love, Viscosity. It's what a would call a perfect "neat little Mac app", funny to say but I get excited when I get to use it. Anyhow, I have a question for you, could you explain what the Preferences->Advanced and tick "Use alternate DNS support" actually does differently?
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Troy Murray

James

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Post by James » Thu Nov 06, 2008 7:25 pm
Hi Troy,

The default set of scripts essentially removes the current Mac OS X DNS settings when you connect, and replaces them with the DNS server/s set by your VPN connection. When the VPN connection is disconnected, the VPN's DNS servers are removed, and the original DNS servers are restored.

The "Use alternate DNS support" option causes Viscosity to use a different approach. Instead of completely replacing the DNS servers, it adds your VPN servers to Mac OS X's DNS system, and gives them a higher priority. This is the nicest way of setting the DNS servers, especially if you use multiple OpenVPN connections simultaneously. While it in theory should work perfectly, some applications that use older techniques to identify the DNS server/s (such as VMWare) may fail to use the correct DNS server.

In a nutshell, ticking "Use alternate DNS support" is only really needed if you are experiencing DNS trouble, or are using multiple OpenVPN connections simultaneously, each with their own DNS server and domain.

Cheers
James
James Bekkema
Viscosity Developer

Web: http://www.sparklabs.com
Support: http://www.sparklabs.com/support
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troymurray

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Post by troymurray » Fri Nov 07, 2008 12:53 am
James,

Great explanation, thank you, makes sense to me now. :D
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Troy Murray

troymurray

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Post by troymurray » Fri Nov 07, 2008 2:39 am
James wrote:
In a nutshell, ticking "Use alternate DNS support" is only really needed if you are experiencing DNS trouble, or are using multiple OpenVPN connections simultaneously, each with their own DNS server and domain
I can have multiple OpenVPN connections at once, I didn't know that, man I love this stuff, thanks!
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Troy Murray

innocent bystander

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Post by innocent bystander » Sat Jan 03, 2009 2:22 am
James wrote:
In a nutshell, ticking "Use alternate DNS support" is only really needed if you are experiencing DNS trouble, or are using multiple OpenVPN connections simultaneously, each with their own DNS server and domain
what traffic goes over which connection if I connect to several identical vpn-servers at different locations? is it random?

James

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Post by James » Thu Jan 08, 2009 5:03 pm
what traffic goes over which connection if I connect to several identical vpn-servers at different locations? is it random?
It depends on how you have set up your routing for each connection. If you edit your connection and go to the Networking tab, you'll be able to specify routes. You can specify what traffic should use the VPN connection, and what traffic shouldn't. By default all traffic on the VPN subnet will be sent through the VPN.

If you have multiple connections with "Send all traffic over VPN connection" checked, then it depends on the order you have connected as to which one all traffic goes through (the last one connected).
James Bekkema
Viscosity Developer

Web: http://www.sparklabs.com
Support: http://www.sparklabs.com/support
Twitter: http://twitter.com/sparklabs
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