Sometimes I have the need for either temporary access, or a dedicated box to access a customer’s network remotely in a secure fashion. This remote access can be accomplished using software that I can install on a customer’s computer, but sometimes that is not possible….either the customer doesn’t want extra software running on their computers, or there’s not a good computer to install it on. In those cases I use a modified Linksys NSLU2 device running a version of Linux that is configured to provide for secure remote access.

Remote Access using a Linksys NSLU2

How it works

From my computer, I run an SSH Tunnel program (See my previous article Access data behind your Firewall from inside the customer’s location …its the same software) that uses the Secure Shell (SSH) protocol to establish a “Tunnel” between my computer and my Modified Linksys NSLU2 sitting on the inside of my customer’s network. The customer’s firewall does need to be modified to allow the connection to come in and get redirected to my NSLU2 device in order for this to all work correctly.
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 | Posted by MobileDataGuy | Categories: HowTos, Virtual Office |

In a previous post Access data behind your Firewall from inside the customer’s location I wrote about getting to my data that was behind my company firewall while located on the inside of my customer’s network behind their firewall/proxy server. This was accomplished by using a program called Tunnelier from a company called Bitvise. Tunnelier allows you to create an SSH tunnel through the local web proxy and over to my company SSH Server, while on my local laptop it starts a SOCKS proxy for local programs (like IE or Firefox) to connect to and thus be able to reach my company’s data while remote. A problem arises though when the program that you want to use….most notably Opera Web Browser in my case…does not support the use of SOCKS. Well, there’s a solution to this problem called ProxyCap. It will “Sockify” programs that are opening an outgoing IP connection and redirect it through a proxy. In my case I’m having it redirect to the local SOCKS proxy that Tunnelier has created locally.

So, to continue where my last article left off; To get Opera to use your SSH tunnel, you need to:


1. Define your local SOCKS proxy In this case I have defined a SOCKS v4 proxy on localhost (127.0.0.1) port 8081(I did have the port at 1080 in my last article, but had to change it to resolve a port conflict with another app I was running). Be sure and use SOCKS v4, and not SOCKS v5 as the current version of Tunnelier (11/2007) seems to have an issue with killing the SSH tunnel when too many SOCKS v5 clients are talking to it. SOCKS v4 does not exhibit this issue.

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 | Posted by MobileDataGuy | Categories: HowTos, Virtual Office |

The Computing Technology Industry Association (CompTIA) accounced a New SMB Survey today that discusses SMB company’s use of mobile technologies. To me, one stat really stood out: one third of all SMB compaines are or will use VPN technology within the next 12 months. That’s quite a large number of folks! There’s hope for my business yet!

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 | Posted by MobileDataGuy | Categories: Opinions, Virtual Office |

If your like most business users, you have some sort of security device, most commonly known as a ‘firewall’, between your computers at work and the Internet. Its there to keep the bad guys from getting to your data. Trouble is, when your not there and your out and mobile, it also does a really good job at keeping you out too. So there needs to be a way to let you back in (in a secure way) and still keep the bad guys out.

One way to do that is to use some sort of access software. Just do a web search on ‘VPN’ and you will find all sorts of solutions. I might write about that topic in another blog entry in the future.

This one though is about when you are on-site at your customer, and they have some security software blocking your access out to the Internet. Usually this isn’t a bad thing, as they usually have some sort of Proxy Server that allows you a path out of their corporate network. Trouble is, this path almost never allows your VPN software out either. If all you need to do is surf the web, then you just need to set up your web browser for proxy access (Do a web search on your browser…IE or Firefox for example… and “+proxy +server +setup” to find how to do this).

In my case, my business email is on the other side of my firewall, not to mention my client data, so I needed to find away through my client’s proxy server and then be able to get securely through my firewall to my internal network.

My solution was OpenSSH on a server inside my firewall, and a product called Tunnelier from Bitvise. There are many websites out there that describe how to set up OpenSSH. There are also a few commercial packages of SSH for many different operating systems. I used OpenSSH for Linux myself, since I had that on hand and it was already installed.

Tunnelier is software that will “tunnel” Internet connections in a secure and encrypted way over the Internet using one protocol that packages up the real protocol until it gets to your OpenSSH server. Then its unpackaged and sent on to its real destination. The really nice thing about Tunnelier is that I can tell it to go through my client’s Proxy Server first, then over to my firewall and into my OpenSSH server!

Here’s how this all works:

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 | Posted by MobileDataGuy | Categories: HowTos, Virtual Office |