Unable to access specific IP Address

[mattyboy7110]

I have to connect to a VPN at work and sometime last year I was unable to access it. Support was a nightmare and didn't understand the issue so I requested a static IP address and overnight the static IP address came online and my issue disappeared. Fast forward to just before Christmas and the same issue has come up again.

If I connect my laptop to my mobile or to another VPN provider, I can access the IP Address but from my Vodafone broadband, a traceroute gets as far as this gateway and no further. 

 1  192.168.1.1 (192.168.1.1)  4.094 ms  3.096 ms  2.142 ms

 2  84.65.0.1 (84.65.0.1)  8.278 ms  8.983 ms  8.771 ms

To confuse things, when I had the original problem, before my static IP address, this gateway was also the stopping point. After my static IP address though, the gateway never changed but I was able to access my work VPN.

I'm pretty sure Vodafone are blocking my work VPN IP address. I'd rather not put the IP address on here but need to know what I can do to resolve it or just to diagnose the issue so someone will look at it. As I mentioned, when trying to get support for this last year, the issue was not understood and I'd rather not have to go through that experience again. 

What do I do?

[CrimsonLiar]

Unless an IP has been flagged as malicious then Vodafone won't be blocking it.  However, when you use a Virtual Private Network, your traceroutes are "tunnelled" through that Virtual Private Network, and so you won't see much that makes sense if you try to run a traceroute.  I assume you are running a VPN client on your local machine, and that you have to manually start that client every time you need access to your work's systems.  As such the issue is most likely to either be with the network configuration on your own device, or with the configuration of the VPN client you are running.
*Sorry I can't be much more help than this!

[mattyboy7110]

Thanks. VPN aside, we host a website on that same IP address and accessing it via the IP address from any device in my house connected to my Vodafone broadband fails. Using a mobile connection or a VPN connection it works. The traceroute shows where it's getting held up and it's not inside my network. 

[CrimsonLiar]

If your company website is being blocked within Vodafone's network (before it gets into the WWW), then someone will need to contact VFs media team to get things sorted, and if it's the same IP then that could very well be leading to your lack of connectivity.  It should be an easy fix, though it might take a few hours to propagate.
*Marcatel in Mexico currently have one of my domains marked as malicious!!!  Its not significant though!

[mattyboy7110]

I guess my question is how would I know who is blocking the IP address. If I could definitively say I can't access x.x.x.x from y.y.y.y and this is the test I did to prove it then maybe I would get somewhere.

[CrimsonLiar]

The solution may be as simple as to change the DNS servers in your router admin pages (you'll probably need to switch from basic to expert mode) before you can find them.  If changing the DNS servers to say Google DNS (8.8.4.4 & 8.8.8.8) works then it is indeed Vodafone that's the culprit here.  I'm sure we can give you more help if it's needed, but try this for now!
And please let us know how you get on.

[mattyboy7110]

When referencing the IP address directly, DNS is not involved. DNS simply maps a host name to an IP address, for example microsoft.com to 1.2.3.4.

[CrimsonLiar]

So far as we've seen previously, Vodafone's blocking takes place at the DNS level.  I think we've only seen VF block by IP when they've been legally obliged to.  If you are being blocked at the IP level, then it's going to need intervention from VFs technical support, and they're best connected via the social media accounts in the first instance.

[Jayach]

When you say that last year, the same problem was cured by getting a static I.P. (although there is no good reason that should work, unless you informed work of that address), do you still have the same static I.P. address?

Is the website you can't access public facing, or is it only accessible via the VPN? (i.e. it's on a private LAN)

If it is public, there should be no reason you can't give us the URL so we can see if we can access it, thereby proving if it's blocked or not by Vodafone.

[mattyboy7110]

On the basis it is a work thing, I am not giving out the IP on a forum. In answer to your question, I have the same static IP address and nothing has changed on my end.

I believe the issue is a routing issue rather than a network-wide block which is why changing my IP address would have cured it because it would come from a different block of IP addresses and thus routed differently. Some people at work on Vodafone don't have the problem.

The crux of the issue is I can't easily prove it and support don't understand so I'm stuck between a rock and a hard place but I'll give support another go tomorrow via webchat and see how I get on.