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VPN issues

Posted: Sun Aug 07, 2011 2:41 pm
by The Rock
Hi. Need some urgent help.

I'm having issues connecting to my Work's VPN. But it's only happening at home. When I try and connect at my Mum's house, no problems. I spoke to my work's technical support about it and the error messaging I am getting related to ports. Also, the strange part was I was able to connect at Home a few weeks ago, but then all of a sudden I wasn't able to.

So in summary:

1. Was able to initially connect to VPN a few weeks ago at Home.
2. Tried again last week but didn't work.
3. Tried it at my Mums house and VPN worked fine.
4. Spoke to tech support and they said the error related to ports and to check with my ISP as to whether there is any ports blocked.

Here are the ports in question:

L2TP: TCP port 1701
IPSEC: UDP port 4500 (NAT -T)
UDP port 500 (isakmp) ~
IP Protocol 50 (Encap Security Payload)
IP protocol 51 (Authentication Header)
IP protocol 47 GRE (Generic Routing Encapsulation)

Am I am to get someone to check if these ports are bneing blocked?

Re: VPN issues

Posted: Sun Aug 07, 2011 4:33 pm
by jokiin
The Rock wrote:
Am I am to get someone to check if these ports are bneing blocked?
Exetel don't block any ports, suggest checking your configuration again as something must be configured incorrectly

Re: VPN issues

Posted: Sun Aug 07, 2011 5:36 pm
by The Rock
But how come it works using a different ISP? What configuration am I supposed to be checking?

Re: VPN issues

Posted: Sun Aug 07, 2011 7:24 pm
by jokiin
The Rock wrote:But how come it works using a different ISP? What configuration am I supposed to be checking?
unless you are using the same computer/router/connection type at each location the fact that it works at one location and not another isn't that relevant, start by checking the settings on your router at the problem site as a starting point

Re: VPN issues

Posted: Sun Aug 07, 2011 7:28 pm
by The Rock
So what setting should I check on my router?

Re: VPN issues

Posted: Sun Aug 07, 2011 8:55 pm
by jokiin
The Rock wrote:So what setting should I check on my router?
no idea what router you have and how it is currently configured, some routers have settings specific to VPN access, others don't, some detail about what you have, how it is configured and what you have tried would be helpful if you would like some assistance to get it working, there is nothing on Exetel's end though that would restrict you from using a VPN

Re: VPN issues

Posted: Mon Aug 08, 2011 4:04 pm
by The Rock
I have a ADSL2+ NB6Plus4Wn.

What do you mean, how it is configured? What information would be helpful? I'm not exactly very technical, I can log into the router and see all the settings etc, but don't know what to look for really. I can't see anything specific to VPN.

Re: VPN issues

Posted: Mon Aug 08, 2011 4:35 pm
by jokiin
The Rock wrote:I have a ADSL2+ NB6Plus4Wn.

What do you mean, how it is configured? What information would be helpful? I'm not exactly very technical, I can log into the router and see all the settings etc, but don't know what to look for really. I can't see anything specific to VPN.
I'll have a look at the manual for your model later when I get a chance, which OS are you using and which VPN protocol?

Re: VPN issues

Posted: Mon Aug 08, 2011 4:45 pm
by The Rock
Well to connect to VPN, I am using Windows 7 OS.

As for VPN Protocol - I'm not sure, but this might help:

L2TP: TCP port 1701
IPSEC: UDP port 4500 (NAT -T)
UDP port 500 (isakmp) ~
IP Protocol 50 (Encap Security Payload)
IP protocol 51 (Authentication Header)
IP protocol 47 GRE (Generic Routing Encapsulation)

Re: VPN issues

Posted: Mon Aug 08, 2011 5:14 pm
by jokiin
The Rock wrote:Well to connect to VPN, I am using Windows 7 OS.

As for VPN Protocol - I'm not sure, but this might help:

L2TP: TCP port 1701
IPSEC: UDP port 4500 (NAT -T)
UDP port 500 (isakmp) ~
IP Protocol 50 (Encap Security Payload)
IP protocol 51 (Authentication Header)
IP protocol 47 GRE (Generic Routing Encapsulation)
is this a laptop, were you connecting at the other location using the same laptop/same settings so just the location and router/internet connection used was different, is that correct?

Re: VPN issues

Posted: Mon Aug 08, 2011 10:06 pm
by The Rock
That is correct.

Re: VPN issues

Posted: Tue Aug 09, 2011 10:02 am
by jokiin
The Rock wrote:That is correct.
given that you could connect previously but now can't, have you rebooted your router since?

as a starting point (for testing purposes) I'd probably set your computer up in the DMZ of the router and see if you can connect then

Re: VPN issues

Posted: Sun Aug 14, 2011 6:50 pm
by The Rock
Yes, the router had been rebooted multiple times since.

Anyway, today I got a new router to see if that would work. And nope, still exactly the same. Completely different router and the exact same problem. Yet I go to my parents place and I have no problems connecting. I also tried it next door, no problems.

So it's not an issue with the router or PC, it's something else.

Re: VPN issues

Posted: Sun Aug 14, 2011 7:18 pm
by jokiin
The Rock wrote:Yes, the router had been rebooted multiple times since.

Anyway, today I got a new router to see if that would work. And nope, still exactly the same. Completely different router and the exact same problem. Yet I go to my parents place and I have no problems connecting. I also tried it next door, no problems.

So it's not an issue with the router or PC, it's something else.
testing with another router is a good idea, it doesn't always mean it still isn't related to the setup of your router though, Exetel don't block any ports so if the same computer connects fine at another location your computer doesn't look like the culprit, what sort of router did you try with just now?

Actually I forgot to ask, do you reboot your computer between locations or do you just close the lid and let it go into standby?

Re: VPN issues

Posted: Mon Aug 15, 2011 1:18 pm
by The Rock
The router I used to test is the same one I used at my parents place, where it worked fine. So I just brought the router over to my place, pluuged it in, set her up....and still doesn't connect. Yet I have no problems with it at all when I take that router back to my parents place and try it there. I also borrowed next door's router, doesn't work. I also tried to access VPN with the router based back at my neighbours house...and yep you guessed it, no problems at all. :shock:

And yes, computer has been rebooted many times between locations.

So I've tried 2 other routers at my house - All don't work.
Can't be an issue with my PC as it works fine at other locations with no problems.
Even tried changing my IP address and all sorts of other fiddly things but to no avail.
Exetel say they don't block any ports so apparantly it can't be exetel.

I am truly stumped now.