Archive for the 'Networking' Category

JoikuSpot - A WiFi Spot on your Mobile

JoikuSpot is a free mobile software solution that turns Nokia Smartphones to WLAN HotSpots.

JoikuSpot software is installed directly to the phone. When switched on, laptops and ipods can establish instant and fast wireless internet connection via smartphone’s JoikuSpot access point using phone’s own 3G internet connection.

Multiple devices can connect to JoikuSpot in parallel and seamlessly share the same 3G internet connection. JoikuSpot acts thus as an internet gateway to external WLAN devices.

Useful isn’t it? :)

Little Snitch 2.0 Beta 6

Little Snitch is a Mac OS X app that runs in the background and hooks with the kernel. As the name indicates, Little Snitch warns you when an application tries to make a network connection, asking you to decide if you allow, deny or add a permanent rule for that specific app in future connections.

A good amount of information on the connection being made is presented to the user, and on version 2 (still in beta), besides the improved network filtering, a visual Network Monitor has been implemented, allowing the user to have real time access to the connections as well as some some send / receive icons like Zone Labs’ Zone Alarm. The configuration interface has suffered some changes and it’s now more functional and user friendly than the previous version.

Jack?

I’m getting a few hits from someone with this user agent: JACK-O`-LANTERN/1.1

I’ve googled it and came and found nothing… Does anyone know who’s using this?

Your Own Personal Mail Server

Are you sick of having all your mail spread arround on your computers? When you have more than one pc, or even if you check your email at work and then at home, it’s a nightmare to keep track of so many emails. And if you’re like me, I have multiple mail accounts, meaning more mail from diferent sources, well the solution isn’t spending all your day sending mail back and forward from one account to another. The solution is actually preety simple: IMAP!

This how to covers Ubuntu 6.06 Server (yes the server version of Ubuntu duh!) but it’s preety simple to adapt to other distros. Let’s start!

Be warned that you may loose some email messages in the process so test this first with a dummy account!

Assuming you have Ubuntu installed and updated, open a shell and type:

mkdir Maildir
(create this on your home folder)

sudo apt-get install dovecot

Let it install all the packages need for dependecies.

Dovecot is an open source IMAP and POP3 server, is very simple to install / configure and suports the Maildir format which is a standard and the one we’re going to use. Dovecot is very complete and has several options, most of them related to security, I’m not covering those so feel free to explore.

So, back to the shell and enter:

sudo nano /etc/dovecot/dovecot.conf

Now change the following:

# Protocols we want to be serving:
# imap imaps pop3 pop3s
#protocols = imap imaps
#protocols = imap imaps

to

# Protocols we want to be serving:
# imap imaps pop3 pop3s
#protocols = imap imaps
protocols = imap imaps

Save the file and run dovecot:

sudo /usr/sbin/dovecot

And now test your IMAP Server:

mutt -f imap://yourusername@localhost

You should get a little nagging about the certificates but after that you enter your password and you should be able to see your empty IMAP folder.

Now the next part is to get the email from the other accounts and for this we’re using a little app named Getmail. Getmail can check your POP and IMAP accounts, I’ll cover only the POP accounts but there’s some examples you can check. Getmail also features some very usefull mail sorting options you can check later.

So, if you’re using Ubuntu 6.06 “normal” then you should be able to download Getmail via apt-get:

sudo apt-get install getmail

If you’re using the Ubuntu server version you won’t get this package via apt-get unless you add the right repository or download the package and install it manually:

wget http://archive.ubuntu.com/ubuntu/pool/universe/g/getmail4/getmail4_4.4.3-1_all.deb

dpkg -i getmail4_4.4.3-1_all.deb

Now comes the lame part :P

You’ll have to write a little configuration file for each of the POP / IMAP accounts you want to check. I’m going to give you an example for a regular POP account and for a GMAIL account.

Again, back to the shell and type:

cd
cd .getmail
touch gmailrc
sudo nano gmailrc

The configuration file for a GMAIL account:

[retriever]
type = SimplePOP3SSLRetriever
server = pop.gmail.com
port = 995
username = yourusername@gmail.com
password = yourpassword

[destination]
type = Maildir
path = ~yourhomedirectory/Maildir/

[options]
delete = true

Save it and repeat the process for a regular POP account:

touch ispmailrc
sudo nano ispmailrc

[retriever]
type = SimplePOP3Retriever
server = pop3.myisp.com
username = yourusername@myisp.com
password = yourpassword

[destination]
type = Maildir
path = ~yourhomedirectory/Maildir/

[options]
delete = true

Save and test it:

sudo /usr/bin/getmail --rcfile=gmailrc

If all goes well you’ll get a few messages like this:

getmail version 4.4.3
Copyright (C) 1998-2005 Charles Cazabon. Licensed under the GNU GPL version 2.
SimplePOP3SSLRetriever:username@gmail.com@pop.gmail.com:995:
0 messages retrieved, 0 skipped

This means Getmail is working, now send yourself some messages to your accounts to test it and run getmail again to check if it delivers to your IMAP folders. You can check it using Mutt like we did earlier.

By now everything should be working perfectly, we just have to automate the email checking. Let’s use crontab. Go to the shell and enter:

crontab -e

Now copy this line and save the file:

* * * * * /usr/bin/getmail --rcfile=gmailrc --rcfile=ispmailrc >> /dev/null 2>&1

(this has to be all in one line, don’t break it or it won’t work correctly!)

And we’re done! Now use an IMAP compatible client like Mozilla Thunderbir or Evolution and you’ll never have to worry with email again.

Ubuntu 6.06 and WPA

Last week after recieving the Ubuntu cds from Canonical as usual, I installed Dapper on my Asus A2 laptop. Installation went fine, except for the same old problem with my SMC 2835 wireless pcmcia card. Once again I had to go through all that process of getting my wireless connection working, but this time I took an alternative road.

- First of all install Automatix, this script will install the NDISWrapper and Gnome NetworkManager packages need to simplify the process.

- If you do a ifconfig you’ll probably see your wireless card listed as eth2, this will change later to wlan0.

- Make sure you have the NDISWrapper installed doing ndiswrapper on a terminal window. If you get a “command not found” error then something went wrong with Automatix, make sure you check the wreless networking packages. If you get an error response from the NDISWrapper that’s fine, it means you have it installed.

- This is one of the most important steps. Ubuntu loads the Prism54 kernel module, but this conflicts with the NDISWrapper, so you’ll have to sudo rmmod prism54 and then sudo gedit /etc/modprobe.d/blacklist and add the line blacklist prism54 to the file and save.

- Reboot.

- Now, download the SMC 2835 Windows XP drivers, unpack and install with Windows Wireless Drivers (System > Administration > Windows Wireless Drivers and then Install New Driver).

- By now your Wireless NIC should be listed as Wlan0 on ifconfig.

- You should have the Gnome NetworkManager applet on the Gnome panel near the clock, click it and choose “Connect to Other Wireless Network” and you’ll see WEP and WPA options. Just enter your Wireless Network SSID and password and you’re done.

You can probably adapt this mini tutorial to another wireless nic so let me know if this works with you.

DNS and the B(L)IND

I recently changed my domain to this server. Everything went well except for the pain on the behind that was the DNS. After wating more than 72 hours for the TLDs to update (with no sucess), I had to change the DNS server where my domain was registred (again). Another problem I came across was with my ISP’s secondary DNS server. It had a different records than the primary name server, so once in a while I got no access to my mail accounts. Once I flushed the DNS cache everthing went fine, but minutes later I got the wrong ip adress AGAIN.

Now everything seems to be working fine, but I decided to catch up on some reading to refresh my knowledge on DNS. I found a very nice link collection on Linux Journal, check it out.

The Open Source version of DNS
OpenNIC: Democratic Name System DNS
Tutorials, Tips and Tricks, HowTo and other Articles
DNS Concepts
DNS HOWTO
DNS tricks and tips
DNS for Rocket Scientists
Internet Domain Name Structure
Domain Name System
Men & Mice - DNS Resources
Setting Up Your New Domain Mini-HOWTO
How to Use Domain-Based Blacklist Zones
Bind and Dnsmasq
freshmeat.net: Project details for Dnsmasq
Configuring BIND with Webmin - RimuHosting
BIND 9 Administrator Reference Manual
Berkeley Internet Name Domain (BIND)
Free DNS hosting
The Public DNS Service
List of free DNS hosting sites
Another list of free DNS hosting sites
Setting up Dynamic DNS at Home
How To Set Static and Dynamic DNS for Your ISP
Free Dynamic and Static DNS
Dynamic Network Services
Online Tools for the Beginner to play with
DNS, Network and other tools.
Expired Domain Name Search
E-Mail relay, DNS, Network and other tools

Nyxem.E

Following the news over the F-Secure site, I’ve noticed that the Nyxem.E worm has been ranked as a Level 2 Alert (meaning that is only one level below the highest alert level). This guy is spreading like mad all over the world from the USA to Australia. The web counter used by the Nyxem worm now shows over 510,000 infections and keeps rising.

The ‘Nyxem.e’ is a mass-mailing worm that also tries to spread using remote shares. It also tries to disable security-related and file sharing software as well as destroys files of certain types. It is similar to the ‘Email-Worm.Win32.VB.bi’ that was found a few days ago.

The worm’s destructive payload is activated on every third day of the month and replaces the content of user’s files with a text string “DATA Error [47 0F 94 93 F4 K5]“. Among these files are: DOC, XLS, MDB, MDE, PPT, PPS, ZIP, RAR, PDF, PSD and DMP.

You can get more info on Nyxem.E here.

Dump

Dunno wich Linux distrib is the best for you? Check the Linux Distribution Chooser.

Speaking about Linux, In my daily basis I’ve been blessed to work with Window$ at full time. Sometimes I have to retrieve and edit information from several text files and logs in order to troubleshoot problems that occurr. Not having a single Linux box in our network (except the proxy), I was in need to find utilities like tail, grep and other gnu/linux utils that worked in win32. I could install Cygwin, but I rather have something native instead of an emulated environment, so I installed UnxUtils - native Win32 ports of the GNU utilities I was looking for. It works like a charm!

Other app that I call essential is UltraEdit 32. Although it’s paid software, UltraEdit has great feautures.

Skipping to another topic: Reading.

I would like to share with you two excelent pieces of tech literature. One is a free book on Asterisk provided by OReilly , the other is a tutorial on Subnets.

Ubuntu and VNC

A few weeks ago I gave Ubuntu another chance. The update bug was corrected and now I could enjoy my Ubuntu box without losing too much time with bugs. My ULAMP (the U is from Ubuntu) box was now ready to work, the only thing missing was the remote access. I installed SSH and explored the Remote Desktop feature that comes with Ubuntu. VNC based, worked well, fast and functional, but when you logoff there’s no more Remote Desktop available. I needed VNC available from the login screen, or GDM in Gnome/Ubuntu. So here’s a quick how to:

First, disable Desktop Sharing under System -> Preferences -> Remote Desktop.

Now install x11vnc, you can do this with apt-get or Synaptics, this package is available in the Community Maintained (Universe) repository.

Now with x11vnc installed, you will need to create a password file:

sudo x11vnc -storepasswd yourpasswordhere /etc/x11vnc.pass

Then configure GDM to run x11vnc when at loading time:

sudo gedit /etc/X11/gdm/Init/Default

and this line to the file:

/usr/bin/x11vnc -rfbauth /etc/x11vnc.pass -o /tmp/x11vnc.log -forever -bg -rfbport 5900

(you can change the port and other parameters)

So far so good, but if you restart your pc at this stage you’ll only be able to login, then the GDM will kill your session. To avoid this we must change another file:

sudo gedit /etc/X11/gdm/gdm.conf

now search for this line :

#KillInitClients=true

And change it to this:

KillInitClients=false

Restart you PC and now you have VNC at login time. :)

Welcome to the FON Revolution

If you have a wireless router at home or at work, you might consider joining the FON movement.

What is FON?
FON is a firmware update that allows you to create a WiFi hotspot at home or at your office (as long as you have a Linksys WRT54G or WRT54GS), allowing others to safely share your connection. The bandwidth of your equipment will be controlled in such a way that you will always maintain a reasonable capacity for your own use in your local network. That limit is independent of the number of Foneros (aka FON users) that are connected to your joining point, but this is not yet implemented in this first release. But enough of tech stuff, the cool feature of FON is that you have three kinds of users, the Linus, the Bills and the Aliens.

The Linus - Inspired in Linus Torwalds and the OSS movement, this users allow full share of their connection to the other users, including the Bills and the Aliens.

The Bills - Guess who? The outline is easy: they’ll get 50% of the money generated by Aliens using Bills access points. In 2006 a billing system will be ready to begin earning money.

The Aliens - Aliens are users of the FON network that don’t have an access point and connect through Linus or Bills. Fees are 5€ for 24 hours of connection and 40€ for one month.

This project is brand new, with lots of work to accomplish, but the idea is there. This could help you pay your Internet bills or even provide you with a better and cheaper WiFi coverage than an ISP can. I hope they add new firmwares soon and include my SMC Barricade router.

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