Escaping Restrictive/Untrusted Networks with OpenVPN on EC2


Perhaps you are behind a corporate firewall which does not allow you to access certain types of resources on the Internet. Or, perhaps you are accessing the Internet over an open wifi where you do not trust your network traffic to your fellow wifi users or the admins running the local network.

These instructions guide you in setting up an OpenVPN server on an EC2 instance, sending all your network traffic through a secure channel to port 80 on the EC2 instance and from there out to the Internet.

EC2 Instance

Run the latest Ubuntu 9.10 Karmic image. You can find the most current AMI id in a table on

ec2-run-instances --key <KEYPAIR> ami-1515f67c

Make a note of the instance id (e.g., i-6fceba06). Watch the status using a command like this (replace with your own instance id):

ec2-describe-instances <INSTANCEID>

Repeat the describe instances command until it shows that the instance is “running” and make a note of the external hostname (e.g.,

Connect to the instance using the external hostname you noted.

ssh -i <KEYPAIR>.pem ubuntu@$remotehost

OpenVPN Server

Upgrade the EC2 instance and install the necessary OpenVPN software:

sudo apt-get update &&
sudo apt-get upgrade -y &&
sudo apt-get install -y openvpn
sudo modprobe iptable_nat
echo 1 | sudo tee /proc/sys/net/ipv4/ip_forward
sudo iptables -t nat -A POSTROUTING -s -o eth0 -j MASQUERADE

Generate a secret key for secure communication with OpenVPN:

sudo openvpn --genkey --secret ovpn.key

Start the OpenVPN server on the EC2 instance. We are (ab)using port 80 because most closed networks will allow traffic to this port ;-)

sudo openvpn                       --proto tcp-server               --port 80                        --dev tun1                       --secret ovpn.key                --ifconfig     --daemon

OpenVPN Client

Back on the local (non-EC2) workstation, set up the software:

sudo apt-get install -y openvpn
sudo modprobe tun # if necessary
sudo iptables -I OUTPUT -o tun+ -j ACCEPT
sudo iptables -I INPUT -i tun+ -j ACCEPT

Download the secret key from the EC2 instance:

ssh -i <KEYPAIR>.pem ubuntu@$remotehost 'sudo cat ovpn.key' > ovpn.key
chmod 600 ovpn.key

Start the OpenVPN client:

sudo openvpn                      --proto tcp-client              --remote $remotehost            --port 80                       --dev tun1                      --secret ovpn.key               --redirect-gateway def1         --ifconfig    --daemon

Edit /etc/resolv.conf and set it so that DNS is resolved by the EC2 name server:

sudo mv /etc/resolv.conf /etc/
echo "nameserver" | sudo tee /etc/resolv.conf

You should now be able to access any Internet resource securely and without restriction.


When you are done with this OpenVPN tunnel, remember to shut down the EC2 instance and restore the DNS configuration:

sudo killall openvpn
ec2-terminate-instances <INSTANCEID>
sudo mv /etc/ /etc/resolv.conf

If you have ways to improve this approach, please leave a comment.


These instructions are not intended to assist in illegal activities. If you are breaking the laws or rules of your government or college or company or ISP, then you should understand the security implications of the above steps better than I do and be willing to accept consequences of your actions.

[Update 2009-01-15: Upgrade instructions for Karmic]


"Ubuntu 9.10 Intrepid" should read "Ubuntu 8.10 Intrepid". Interesting article - thanks.

Mark: Fixed, thanks!

Gotta say: love your work Eric. Keep up sharing the goodness and thanks a lot.

Thanks for the howto. I found this really easy to set up.

I'd like to use nonsymmetric keys and use the server with multiple computers. I'm finding the openvpn documentation hard to get into though. Any pointers to tutorials to make those changes?

wibge: Though I have used openvpn with asymmetric keys, it is indeed a lot more work, which is why I didn't choose that approach for a quick tutorial like this. Here are a couple resources which might help in your quest:


Nice article. Could you please also provide a Windows client configuration? I have tried a little myself but cannot get it work. It will help me a lot since tons of websites are blocked here.

mitnickcbc: I've heard about Windows, but I don't have any. You'll need to seek help elsewhere for them.

One server and client, before issuing iptables commands:

sudo iptables-save >/etc/iptables.rules


Following the guide above, I tried to run openvpn on a custom 10gb esb AMI I created from 'Debian 5.0 lenny Server (ami-b1f38ce3)'.

To qualify for the EC2 free tier, I followed this guide
to convert the 15gb Debian 5.0 lenny Server AMI to a 10GB AIM.

Openvpn couldn't find any tun device when it tried to start.
I checked and there wasn't any tun device loaded so I tried to load the tun by placing 'tun' in '/etc/module' and restarting my instance. The tun device didn't load. I read that ec2 doesn't allow kernel modules to be loaded.

I'm not sure where the source of my problem is.
Weather I chosen a kernel without tun compiled when making the 10gb ami or if tun wasn't compiled in 'ami-b1f38ce3' in the 1st place.

What can I do now? Am I still able to enable a tun device for openvpn to work on my current custom AMI?

techntools: The above instructions worked on Ubuntu. I haven't tried Debian.

Combining the above with the info in the link below

gave me a solution to VPN out on Ubuntu and MS-Windows 7 clients via an OpenVPN server running on Ubuntu on hosted cloud service.

The key element for me was the routing on MS-Windows.

I quote:

On your windows client, you’ll now need to change your default gateway:

Use route print and find out your current default gateway, then, assuming your current local default gateway is: and server’s IP address is XX.XXX.124.95, issue the following commands:

route DELETE

route ADD XX.XXX.124.95 MASK

route ADD MASK

The first ADD command is used to tell your client how to access the ‘new default gateway’. Without specifying your real default gateway, the client machine would have no idea how to reach your VPN server.
You can specify as your default gateway, as it is now virtually on the same LAN as your adapter, but without the additional route to XX.XXX.124.95, your connection to the server would have to terminate and you’d lose your tun interface.

Thanks for this guide. Doesn't seem to work with Maverick Meerkat though - after following your instructions and trying to connect to the VPN from the client, I'm getting this error:

Note: Cannot ioctl TUNSETIFF tun1: Operation not permitted (errno=1)
Note: Attempting fallback to kernel 2.2 TUN/TAP interface
Cannot open TUN/TAP dev /dev/tun1: No such file or directory (errno=2)

Ubuntu 10.10 is installed on both client and server. Looking at the output of ifconfig, there is indeed no tun device.


Thanks for pointing this out. I've added a task to my todo list to update this article for modern Ubuntu :)

"sudo iptables -t nat -A POSTROUTING -s -o eth0 -j MASQUERADE"

slash 2? Are we serious? How many hosts does that cover? Even legal?


Looks like a typo. Corrected to "/24"

Leave a comment

Ubuntu AMIs

Ubuntu AMIs for EC2:

More Entries

When Are Your SSL Certificates Expiring on AWS?
If you uploaded SSL certificates to Amazon Web Services for ELB (Elastic Load Balancing) or CloudFront (CDN), then you will want to keep an eye on the expiration dates and…
Throw Away The Password To Your AWS Account
reduce the risk of losing control of your AWS account by not knowing the root account password As Amazon states, one of the best practices for using AWS is Don’t…
AWS Community Heroes Program
Amazon Web Services recently announced an AWS Community Heroes Program where they are starting to recognize publicly some of the many individuals around the world who contribute in so many…
EBS-SSD Boot AMIs For Ubuntu On Amazon EC2
With Amazon’s announcement that SSD is now available for EBS volumes, they have also declared this the recommended EBS volume type. The good folks at Canonical are now building Ubuntu…
EC2 create-image Does Not Fully "Stop" The Instance
The EC2 create-image API/command/console action is a convenient trigger to create an AMI from a running (or stopped) EBS boot instance. It takes a snapshot of the instance’s EBS volume(s)…
Finding the Region for an AWS Resource ID
use concurrent AWS command line requests to search the world for your instance, image, volume, snapshot, … Background Amazon EC2 and many other AWS services are divided up into various…
Changing The Default "ubuntu" Username On New EC2 Instances
configure your own ssh username in user-data The official Ubuntu AMIs create a default user with the username ubuntu which is used for the initial ssh access, i.e.: ssh ubuntu@<HOST>…
Default ssh Usernames For Connecting To EC2 Instances
Each AMI publisher on EC2 decides what user (or users) should have ssh access enabled by default and what ssh credentials should allow you to gain access as that user.…
New c3.* Instance Types on Amazon EC2 - Nice!
Worth switching. Amazon shared that the new c3.* instance types have been in high demand on EC2 since they were released. I finally had a minute to take a look…
Query EC2 Account Limits with AWS API
Here’s a useful tip mentioned in one of the sessions at AWS re:Invent this year. There is a little known API call that lets you query some of the EC2…
Using aws-cli --query Option To Simplify Output
My favorite session at AWS re:Invent was James Saryerwinnie’s clear, concise, and informative tour of the aws-cli (command line interface), which according to GitHub logs he is enhancing like crazy.…
Reset S3 Object Timestamp for Bucket Lifecycle Expiration
use aws-cli to extend expiration and restart the delete or archive countdown on objects in an S3 bucket Background S3 buckets allow you to specify lifecycle rules that tell AWS…
Installing aws-cli, the New AWS Command Line Tool
consistent control over more AWS services with aws-cli, a single, powerful command line tool from Amazon Readers of this tech blog know that I am a fan of the power…
Using An AWS CloudFormation Stack To Allow "-" Instead Of "+" In Gmail Email Addresses
Launch a CloudFormation template to set up a stack of AWS resources to fill a simple need: Supporting Gmail addresses with “-” instead of “+” separating the user name from…
New Options In ec2-expire-snapshots v0.11
The ec2-expire-snapshots program can be used to expire EBS snapshots in Amazon EC2 on a regular schedule that you define. It can be used as a companion to ec2-consistent-snapshot or…
Replacing a CloudFront Distribution to "Invalidate" All Objects
I was chatting with Kevin Boyd (aka Beryllium) on the ##aws Freenode IRC channel about the challenge of invalidating a large number of CloudFront objects (35,000) due to a problem…
Email Alerts for AWS Billing Alarms
using CloudWatch and SNS to send yourself email messages when AWS costs accrue past limits you define The Amazon documentation describes how to use the AWS console to monitor your…
Cost of Transitioning S3 Objects to Glacier
how I was surprised by a large AWS charge and how to calculate the break-even point Glacier Archival of S3 Objects Amazon recently introduced a fantastic new feature where S3…
Running Ubuntu on Amazon EC2 in Sydney, Australia
Amazon has announced a new AWS region in Sydney, Australia with the name ap-southeast-2. The official Ubuntu AMI lookup pages (1, 2) don’t seem to be showing the new location…
Save Money by Giving Away Unused Heavy Utilization Reserved Instances
You may be able to save on future EC2 expenses by selling an unused Reserved Instance for less than its true value or even $0.01, provided it is in the…
Installing AWS Command Line Tools from Amazon Downloads
This article describes how to install the old generation of AWS command line tools. For the most part, these have been replaced with the new AWS cli that is…
Convert Running EC2 Instance to EBS-Optimized Instance with Provisioned IOPS EBS Volumes
Amazon just announced two related features for getting super-fast, consistent performance with EBS volumes: (1) Provisioned IOPS EBS volumes, and (2) EBS-Optimized Instances. Starting new instances and EBS volumes with…
Which EC2 Availability Zone is Affected by an Outage?
Did you know that Amazon includes status messages about the health of availability zones in the output of the ec2-describe-availability-zones command, the associated API call, and the AWS console? Right…
Installing AWS Command Line Tools Using Ubuntu Packages
See also: Installing AWS Command Line Tools from Amazon Downloads Here are the steps for installing the AWS command line tools that are currently available as Ubuntu packages. These include:…
Ubuntu Developer Summit, May 2012 (Oakland)
I will be attending the Ubuntu Developer Summit (UDS) next week in Oakland, CA.  This event brings people from around the world together in one place every six months to…
Uploading Known ssh Host Key in EC2 user-data Script
The ssh protocol uses two different keys to keep you secure: The user ssh key is the one we normally think of. This authenticates us to the remote host, proving…
Seeding Torrents with Amazon S3 and s3cmd on Ubuntu
Amazon Web Services is such a huge, complex service with so many products and features that sometimes very simple but powerful features fall through the cracks when you’re reading the…
There are a number of CloudCamp events coming up in cities around the world. These are free events, organized around the various concepts, technologies, and services that fall under the…
Use the Same Architecture (64-bit) on All EC2 Instance Types
A few hours ago, Amazon AWS announced that all EC2 instance types can now run 64-bit AMIs. Though t1.micro, m1.small, and c1.medium will continue to also support 32-bit AMIs, it…
ec2-consistent-snapshot on GitHub and v0.43 Released
The source for ec2-conssitent-snapshot has historically been available here: ec2-consistent-snapshot on using Bazaar For your convenience, it is now also available here: ec2-consistent-snapshot on GitHub using Git You are…