What excactly does "Send all traffic" option in VPN settings do?

Question

Level 1

8 points

What excactly does "Send all traffic" option in VPN settings do?

I tried disabling "Send all traffic" in VPN (PPTP) setting and I have problem understanding what exactly is happening.

- Phone is getting 192.168.4.0/24 address from the pool.

- Gateway is on 192.168.4.1 (DNS also)

There is no problem with contacting gateway and DNS but if I try connecting to 192.168.0.0/16 it will not use VPN and after a while it says "Cannot connect".

Every other public address works fine and phone is contacting my DNS for resolving every address.

Also, when I ping phone from, for ex. 192.168.1.0/24 it responds normally (it sends icmp packets back from where they came from).

Does anyone knows how can i set it up to use VPN for private addresses (in my case 192.168.0.0/16) and for everything else to use 3G or wifi connection?

Thanx.

iPhone 4S, iOS 5.1.1

Posted on Aug 1, 2012 2:44 AM

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Answer 1

Best reply

leonfrombrunssum

Level 1

25 points

Aug 1, 2012 6:35 AM in response to UCBS

Hi there,

I have some experience with this kind of play.

Send all traffic means that your iPhone will redirect every single ip-based information request via the VPN tunnel through your VPN server, to the internet.

If you disable Send All Traffic, your iphone will only use your VPN connection if the private ip range cannot be found with other connections (such as; wifi, cellular etc..) so, another trick you can utilize on an iPhone is to configure it with a configuration profile using the apple device configurator from the mac app store, or use profile manager on your mac os x server (10.7 or hirgher). With a profile you can specify vpn on demand. This means:

whenever you visit a predefined webpage, or you use a predefined ip address, the vpn connection will automaticly be established and the traffic for that specific webpage or ip address wlil automaticly be forwarded through that vpn connection.

It's a lot to take in,

ik hope i helped you,

Kind regards,

Léon van de Broek

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Answer 2

UCBS Author

Level 1

8 points

Aug 1, 2012 7:04 AM in response to leonfrombrunssum

Thanks a lot for your help.

You said "your iphone will only use your VPN connection if the private ip range cannot be found with other connections (such as; wifi, cellular etc..)" but it does not work. When I was testing my phone was only connected to 3G network and wifi was off. So, there were absolutely no accessible private range addresses and it still can't connect to the private range through VPN.

Any idea?

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Answer 3

UCBS Author

Level 1

8 points

Aug 2, 2012 6:30 AM in response to UCBS

Is it possible that nobody knows the answer? I tried looking on the Internet and I could not find the answer anywhere.

😟

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Answer 4

UCBS Author

Level 1

8 points

Aug 2, 2012 9:17 AM in response to UCBS

I was testing various situations and came to solution. I think there is a bug in iOS because it is not routing 192.168.0.0/16 as private but public address space.

As mentioned in my first message in this thread I was using 192.168.0.0/16 but now after I tried assigning 10.0.0.0/8 to the phone's VPN interface everything works perfectly!

I still cannot communicate with 192.168.0.0/16 but communication to devices within 10.0.0.0/8 is working fine even if they are not in the same subnet as phone is.

So, i think that is a bug...

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Answer 5

jake2003

Level 1

0 points

Oct 14, 2012 7:24 PM in response to UCBS

i'm having same issue here. Im trying to configure VPN via PPTP and the only way I could have my Internet working again is when I turn off "SEND ALL TRAFFIC". Is there anyone that could successful enable this feature? If no explain in details what this function "send all Traffic" do to VPN?

thanks

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Answer 6

Oct 18, 2012 10:46 AM in response to jake2003

Hello, I have been having this problem to.

Today i opend up pptpd-options i changed the two dns servers to this

ms-dns 8.8.8.8

ms-dns 8.8.4.4

Googles DNS servers

I am now table to pass all trafic through my VPN connection and use the internet.

If i change them back, and the send all traffic it will connect to the VPN but with no internet.

There seems to be an issure with the DNS.

Anyways this works enjoy.

I also checked with whatsmyip.com to check im not using my 3g internet.

Edit this is working oin the iphone 4 and gallaxy mini

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Answer 7

jake2003

Level 1

0 points

Oct 18, 2012 11:02 AM in response to Bobbyraspberry

Hi,

Thanks for respond. I'm using Synology NAS to connect to VPN and I found out that in configuration setting I have to state DNS of my local router. Once I've done it it I was able to filter all the traffic.

-Jake

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