Issue with PPTP VPN setup

dd-wrtiphonepptpvpn

My first intention to setup a PPTP VPN, via my Linksys E2000 router with DD-WRT firmware, was to use an iPhone app while being connected to my home network from anywhere I have an internet connection. That is working. However I am finding out I cannot check my emails using my iPhone while it is connected to the VPN. But if I am not connected, I can check emails. My VPN client is my iPhone 4 running on iOS 6.1.2.

What could be causing this? Here is my PPTP VPN setup within my router:

pptp server: enable
broadcast support: enable
force mppe encryption: enable
dns1: 208.67.222.222
dns2: 8.8.8.8
wins1: 208.67.222.222
server IP: 192.168.4.1
client ip: 192.168.4.10
Chap-secrets: username * password *

Routing Table:
LAN NET        Subnet Mask       Gateway      Interface 
192.168.4.10   255.255.255.255   0.0.0.0      ppp1
118.23.8.201   255.255.255.255   0.0.0.0      ppp0
118.23.8.201   255.255.255.255   0.0.0.0      ppp0
192.168.1.0    255.255.255.0     0.0.0.0      LAN & WLAN 
0.0.0.0        0.0.0.0           118.23.8.201 ppp0

My router IP is 192.168.1.1

Other. Although these are enabled and set, it didn't make a difference if I shut them off or on. It works both ways. VPN passthrough: all 3 enabled ports forward: 1723 & 1792

Best Answer

The problem is not with your routing table, it looks just fine. What is not correct is however your configuration file, and there might be a problem with the configuration for use with IPhones. I suggest you make a copy of the current file, to be used in case of disaster, but then let us proceed to write a new one.

You can check the proper way to configure your VPN here, but I will walk you through this.

I think the first error is in the WINS2 address. You used an OpenDNS address, while WINS2 should be an address within your LAN; from this I deduce you do not have a WINS2 server on your LAN (most people do not, I certainly don't), so just drop this line. The DD-WRT manual link above states:

WINS Add your local WINS servers. This settings are optional.

(Emphasis mine).

Then the server IP is wrong; the guide states

Server IP. Your LAN IP Address.

You can use your router's LAN address, 192.168.1.1

Then there is the client IP address range. The guide states:

Client IP(s) The client IP range. Leave it blank will not work. ... Should be a valid IP Address on the LAN segment of the network.

Thus it should be within the range 192.168.1.0/24. Please pick a range, not just an individual address, because syntax may be sensitive to the lack of a dash.

Lastly, the peculiarity of IPhones. The same guide, a tad later, here, states that there is a DNS problem with IPhones, and that addition of a few lines to the router start-up script will cure this problem. This point is a bit dubious, because it is not clear whether this DNS problem affects all IPhones, or only some versions of IOS (and thus no point in my asking which one you are using). Thus I suggest you try your VPN without this correction first; then if it fails, you set it up as per the link provided.

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