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Jonas Bonér " Blog Archive " Clustering Scala Actors with Terracotta

Mon, 06 Oct 2008 03:16:55 -0700

Jonas Bonér " Blog Archive " Real-World Scala: Dependency Injection (DI)

Mon, 06 Oct 2008 03:16:45 -0700

XML Paper Specification (.xps): Overview

Mon, 06 Oct 2008 00:43:37 -0700

The XML Paper Specification (XPS) provides users and developers with a robust, open and trustworthy format for electronic paper. The XML Paper Specification describes electronic paper in a way that can be read by hardware, read by software, and read by people. XPS documents print better, can be shared easier, are more secure and can be archived with confidence.

PDF Export - Meta

Sun, 05 Oct 2008 13:59:01 -0700

Quick Linux and Windows OpenVPN HOWTO and tutorial, including VPN routing

Fri, 03 Oct 2008 03:23:57 -0700

http://www.adamsinfo.com/quick-linux-and-windows-openvpn-howto-and-tutorial-including-vpn-routing/

OpenVPN is a popular Windows/Linux VPN Server/Client pair. I think there’s a separate GUI available for it if you’re so minded. This howto will cover command line usage only.

I’ll provide example configuration based on a Linux server and a Windows client, however the same applies pretty easily if you wanted to mix and match.

On debian, apt-get install openvpn. On any other linux distro, use your own package manager or alternatively download from source and compile.

I create my config /etc/openvpn/myvpn.conf and enter the following:

dev tun proto udp ifconfig 10.8.0.1 10.8.0.2 secret /etc/openvpn/static.key comp-lzo keepalive 10 60 daemon

In short, I’m specifying that we’ll use the ‘tun’ interface as opposed to ‘tap’, and that we’ll communicate over UDP. Next I specify that this machine’s tun0 interface will have IP 10.8.0.1 and the client will be given 10.8.0.2. My secret key is stored in /etc/openvpn/static.key which you can generate with openvpn –genkey –secret static.key. I’d like to use comp-lzo for compression and also specify a keepalive time to prevent problems on those networks that terminate idle connections. We’ll also have openvpn daemonize. For the client:

remote XX.XXX.124.95 ;server IP address dev tun ifconfig 10.8.0.2 10.8.0.1 secret static.key comp-lzo keepalive 10 60

This configure is mostly identical to the server’s above.

Now copy the static.key that you generated on the server, to the client. Then just run ‘openvpn config.conf’ it’ll print the relevant debug messages and you’ll be there. At this point, you should be able to ping 10.8.0.1from your client and 10.8.0.2 from your server. If you can, all is good.

On your server, you’ll now need to allow routing so your client is able to route it’s traffic through the VPN:

iptables -t nat -A POSTROUTING -s 10.8.0.0/24 -o eth0 -j MASQUERADE iptables -A FORWARD -i tun0 -s 10.8.0.0/24 -o eth0 -j ACCEPT iptables -A FORWARD -i eth0 -o tun0 -m state –state ESTABLISHED,RELATED -j ACCEPT echo 1 > /proc/sys/net/ipv4/ip_forward

…Or similar to suit your needs.

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: 192.168.1.1 and server’s IP address is XX.XXX.124.95, issue the following commands:

route DELETE 0.0.0.0 route ADD XX.XXX.124.95 MASK 255.255.255.255 192.168.1.1 route ADD 0.0.0.0 MASK 0.0.0.0 10.8.0.1

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 10.8.0.1 as your default gateway, as it is now virtually on the same LAN as your 10.8.0.2 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.

Now try and ping something – it should be successful. If not, get onto the server and run tcpdump -n tun0. If the server is seeing your traffic but not forwarding it to the outside world, chances are your iptables and masquerading is set up incorrectly. If the server isn’t even seeing any traffic from you, then chances are your windows routing setup is incorrect.

Hope this was useful! Comments and feedback are welcome as always.

∞ unlimited edition

Tue, 30 Sep 2008 07:15:24 -0700

Con la herramienta de impresión HP Smart Web Printing puede imprimir publicaciones Web de manera sencilla y previsible, además de controlar los documentos que desea imprimir y la forma en que desea hacerlo.

Tue, 30 Sep 2008 04:15:07 -0700

HP Smart Web Printing enables simple, predictable web page printing.

Mon, 29 Sep 2008 07:22:38 -0700

Indesign: why do i have to override Master pages everytime?

Sun, 28 Sep 2008 18:24:36 -0700

problem solved

[Techtalk] Samba Printer - Access Denied, unable to connect