PPTP Won't work after 4.3 Upgrade

I'm dead in the water too! why apple is ignoring this 😟

Slinge

I can confirm that your iPhone configuration utility steps you laid out Do infact work. It fixed my iPad 1 iOS 4.3.1 I can now connect to my VPN provider HMA just fine. This fix works!

Syrex wrote:

The iOS 4.3 and 4.3.1 devices simply stop sending traffic back after the PPTP server offers it's Configuration Request. Adding either 'nopcomp', 'noaccomp'
or both to /etc/ppp/options.pptpd results in the connections working every time.

In Other Words:
iOS 4.3 and 4.3.1 immediately stop trying to establish a VPN connection
when they are offered both pcomp (protocol field compression negotiation)
and accomp (address/control compression). This is the default behaviour
in PPP and presumably why allot of Linux based routers are subsequently unable
to establish connections with iOS 4.3+.

Is there any way to do the equivalent of adding 'nopcomp' or 'noaccomp' to a Linux options.pptpd on a Windows 7 PPTP VPN server?

Thanks to the work and post by Syrex I have been able to get a workable PPTP connection.

What I have done on my DD-WRT router is add the following to the startup window.
Found here - Administration > Commands > Startup

echo 'noaccomp' >> /tmp/pptpd/options.pptpd

I have verified that it works both over 3G and from another WiFi network connection

I did it this way so all I will need to do is remove command from the startup window if a real fix is released.

Thanks again Syrex

Confirming that this works on iPad 2 and iPhone 3GS w/IOS 4.3.1. Thanks Syrex & Cosworth!

I am running 10.5.8 and so cannot run iphone configuration utility 3.3 to use your solution for vpn on 4.3.1. any ideas ?

Try Syrex & Costworth's method if your using DDWRT

Also you don't need to run the iPhone configuration app on the computer the Idevice is synced with, you can run it on another machine and email yourself the config profile 😉

slinge, tried your advice. email config etc. worked only once when I was on airplane mode. after that it did not work anymore. thanks.

I installed dd-wrt to try to get PPTP working with my Ipad. I had the same problems people are having here (only connected one out of 15 tries).

I had to install Tomato instead because the wireless was so flakey with dd-wrt. But I installed the Tomato with PPTP patches....the PPTP server was a bit of work to get going, but I finally got it, and the firewall rules working.

In this process, I tried a lot of settings for the PPTP server. At first, I had the same problem as dd-wrt. I finally found a solution that worked, just altering the ppp options.

Because I don't have dd-wrt, and they suck for documentation, or even getting to a tarball of the binary/source, I can't tell you where these options should go. (Not a big fan of dd-wrt by this point...trying to troll through their source/binaries to figure out what options it is using.)

From someone elses post above, it looks like this might belong in /tmp/pptpd/options.pptpd

Anyways, the options I am using are:

lcp-echo-failure 3
lcp-echo-interval 60
default-asyncmap
mtu 1482
mru 1482
nobsdcomp
nodeflate
mppe required,no40,no56,stateless
require-mschap-v2
refuse-chap
refuse-mschap
refuse-eap
refuse-pap
proxyarp
ms-dns <enter a DNS server here>

(this requires 128 bit encryption for pptp and ms-chap-v2 for authentication)

I am 90% sure that the reason it works is because I made the mru & mtu smaller than the default. There is a 10% chance that it is the default-async All I know is that I altered all the other options, and finally when I set those 3 options, it started working. It works 100% of the time I try to connect now.

I would try adding this to /tmp/pptpd/options.pptpd by writing this into the script window at 'Administration > Commands > Startup':

echo 'mtu 1482' >> /tmp/pptpd/options.pptpd
echo 'mru 1482' >> /tmp/pptpd/options.pptpd

If that didn't work, I would add

echo 'default-asyncmap' >> /tmp/pptpd/options.pptpd

I hope this helps someone having problems with dd-wrt or linux in general running poptop for a pptpd server.

I have the following problem.
I can connect to the VPN (using L2TP) and I can ping machines in the internal network (in my company).
The problem is that if I try to resolve a name, the DNS don´t work.

DNS resolution problem in VPN, ¿How can I repair it?
In 4.1 mi VPN worked correctly and I have not changed anyting
¿Any idea?

I would try adding this to /tmp/pptpd/options.pptpd by writing this into the script window at 'Administration > Commands > Startup':

echo 'mtu 1482' >> /tmp/pptpd/options.pptpd
echo 'mru 1482' >> /tmp/pptpd/options.pptpd

If that didn't work, I would add

echo 'default-asyncmap' >> /tmp/pptpd/options.pptpd

I just tested both statements above....I guessed wrong. Ignore the mru/mtu (though it couldn't hurt). It is the default-asyncmap that made the difference. With it, I connect right away. Without it in my options, I can't connect.

I've tried the workaround offered up by slinge and it does work although not always - often requires several attempts.

I can confirm that this works on my setup as well on a DD-WRT flashed router.

I just used the following in startup window

echo 'default-asyncmap' >> /tmp/pptpd/options.pptpd

It did not connect on first attempt, I connected to my work VPN and then tried again and it seems OK now.

echo 'default-asyncmap' >> /tmp/pptpd/options.pptpd

I confirm that Cosworth's startup command does work (after 2nd connection attempt). Thank you Cosworth!

iOS 4.3.2

DD-WRT build 15943M