vincentkong.com » Networking

Networking Browsing with pyNeighborhood in Xubuntu 8.10

Vincent Kong — Tue, 03 Feb 2009 04:36:56 +0000

Prior to Xubuntu 8.10 I used SMB for FUSE for networking browsing. However, after upgrading to 8.10 I found that I would get an error: Transport endpoint is not connected everytime I try to copy a file to my Windows desktop using Thunar. Apparently, this is a known bug with fusesmb, therefore after searching for an alternative solution I found pyNeighborhood.

Installing pyNeighborhood

$ apt-get install pyneighborhood

Configuring pyNeighborhood

Setup the directory which is to be mounted

$ cd /media
$ mkdir network
$ chmod 777 network

From the panel bar of Xfce select “Application”, “Network”, and “pyNeighborhood”

Select “Edit”, and “Preferences”
Under the “General” tab, enter the “Mount folder:” e.g. /media/network

Under the “File Managers” tab, remove the entry xterm -e mc, and add /usr/bin/thunar as the file manager

Adding a Mountpoint

In the pyNeighborhood under the “Network” tab, right click “Groups” to scan your network groups

Right click the network group found to scan the machines in the selected network

Right click the machine to add it to the right panel

Expand the machine, and right click on a shared folder to mount it

Creating static IP in Xubuntu 8.10

Vincent Kong — Thu, 15 Jan 2009 13:00:38 +0000

Ubuntu 8.10 ships with Network Manager 0.7, which comes with many features. Unfortunately, I had a difficult time trying to assign a static IP to my computer as it would get lost after each restart. I wasn’t the only one with this problem and here’s how it’s done:

Right click on the “Network Manager” icon and select “Edit Connections…”
Delete any “Auto” settings, and click “Add”

Network Manager

Click on the “IPv4 Settings” tab, and enter your network information.
Make sure you check the “System setting” checkbox. Click “OK” when done

Network Manager IPv4 Settings

DD-WRT v24

Vincent Kong — Fri, 06 Jun 2008 22:31:08 +0000

When I flashed my Linksys WRT54GL router last year in July with the DD-WRT v23 SP2, the version has already been around since September 2006.

The default firmware for Linksys has a severe problem where they track old connections for FIVE days, which causes the router to hang when using software that generates a lot of connections.

The DD-WRT v24 was recently released on May 18, 2008 and I was more than happy to flash my router with the new version.

The project comes in 6 different version: Micro, Mini, Standard, VOIP, VPN, Mega. I downloaded and installed the V24_mini_generic.bin as recommended by the Supported Device page. The flashing took about 2 minutes to complete, and all the settings on the router will reset. The default username is “root” and password is “admin” for the DD-WRT control panel.

IBM Thinkpad Unauthorized Network Card

Vincent Kong — Wed, 04 Jun 2008 04:19:44 +0000

A week ago my wireless network card died on my IBM Thinkpad T42. I visited the IBM shopping website to look for the Intel Pro/Wireless 2200BG and found it cost approximately $80 not including taxes and shipping. Knowing the price tag was totally unreasonable, I looked somewhere else, and I ended up getting it at Dell for half the price!

After the network card arrived, I immediately replaced the card and booted up my laptop. Next thing I know, I see an error message:

1802: Unauthorized network card is plugged in Power off and remove the miniPCI network card.

Apparently IBM insists on only accepting “IBM brand” wireless cards through a restriction set in the BIOS. However, there is a fix available for the 1802 error: a DOS program no-1802.com, which will flip a single bit in the CMOS, allowing use of any Mini-PC wireless card.

I disabled the wireless card through the BIOS, to avoid having to physically remove it. Then follow the steps to apply the fix:

Download no-1802.com
Boot the laptop in DOS mode
Run no-1802.com

Nothing happened after running the command, I rebooted the laptop and re-enable the wireless card from the BIOS. The laptop was able to boot without any issues, and I’m able to use my new wireless card successfully!

For better conveniences, I downloaded bootable CD image which allowed me to boot in DOS. A floppy disk image is also available to download as well.

For more information refer to ThinkPad 1802 Error Fix or Problem with unauthorized MiniPCI network card.

Network Browsing with Xubuntu

Vincent Kong — Sun, 03 Feb 2008 16:32:52 +0000

Unlike like Ubuntu’s default file manager Nautilus for the GNOME desktop, the default file manager Thunar from Xubuntu doesn’t support samba/network browsing.

Nautilus Share

An easy workaround is to install the Nautilus Share package. When installing the Nautilus Share package other related Nautilus packages which will also included such as the Nautilus file manager which may be used to replace the Thunar file manager.

To install Nautilus Share:

$ sudo apt-get install nautilus-share

SMB for FUSE

A more complex workaround is to use SMB for FUSE packages and will allow you to keep using Thunar.

The first requirement is to have Samba installed, an easy to tigger the install is by going to the following in the Xfce desktop: Applications -> System -> Shared Folders
Install fusesmb:
$ sudo apt-get install fusesmb
Ensure that fuse module will be loaded at boot time
$ sudo nano /etc/modules
and look for fuse in the list
Reboot the server to load the fuse module
Allow users to use fuse:
- Go to Application -> System -> Users and Groups
- Click on the “Properties” button of the username
- Under the “User Privileges” tab check the “Allow use of fuse fileystems like LTSP Thin Client blockdevices” checkbox
Create a directory with the following settings to mount the network browse to:
$ mkdir /media/network $ chmod 777 /media/network $ chgrp fuse /media/network
Add your user account to the fuse group
$ nano /etc/group
or go to Application -> System -> Users and Groups, and click on the “Manage Groups” button
Reboot the server again
Go to to menu Application -> Settings -> Autostarted Applications, and add a new entry with the following command: /usr/bin/fusesmb /media/network
Open Thunar and add parent folder of the mount point e.g. network to the shortcut pane of Thunar
Logout and log back to enable to fusesmb autostart to take effect.

Troubleshooting

Can’t see a new shared computer or folder in Thunar.

In the terminal type the following to refresh fusesmb
$ fusesmb.cache

Blue Screen of Death on IBM Thinkpad

Vincent Kong — Wed, 05 Dec 2007 03:23:45 +0000

I’m an owners of two IBM Thinkpad; the T40, and the T42, both running on Windows XP. A few days ago both of were experiencing problems with the laptops.

With the T42 Thinkpad, I would lose my wireless connection a few moments after I have turned on the laptop. When I try to ping my router I would get a “Hardware Error” message, and when viewing the Network Connections under Control Panel, the Wireless Connection indicated that it was disabled. An attempt to re-enable the connection would result in the laptop hanging.

The T40 Thinkpad was even worse, as it was haunted by the Blue Screen of Death.The blue screen would appear randomly and very frequently, making it almost impossible to diagnose what was the cause.

It turned out the root case was the drivers for the Intel PRO/Wireless 2200BG wireless card, which is the card that was installed on both our laptops.Apparently, the existing drivers which came with the IBM Thinkpad was no longer compatible with newer Access Points (I had also recently change my wireless network encryption from WEP to WPA).I downloaded the latest drivers from, and after installing it, both laptops were working again.

For more information refer to the Intel WiFi Product support page.

Optimizing My Router with DD-WRT

Vincent Kong — Mon, 09 Jul 2007 03:54:25 +0000

Last week I flashed my Linksys WRT54GL router with a 3rd party firmware DD-WRT v23 SP. The installation resolved my issues with the original Linksys firmware of not being able to surf the internet while downloading with bittorrent. However, I found connectivity was still a bit sluggish and at times it was difficult to access the DD-WRT web administration interface.

I found some performance tips related to router slowdown from the DD-WRT Wiki website, and implemented one of the solutions recommended on the page:

Go to the Web-Admin and log in
Go to ‘Administration’
Go to ‘Management’
Enter the following values at ‘IP Filter Settings’
- Maximum Ports: 4096
- TCP Timeout (s): 3600 to 90 (decrease if you have many TCP connections)
- UDP Timeout (s): 3600 to 90 (decrease if you have many UDP connections)

This weekend, I was assigned to do load testing from my home for a project at work. The load testing involved running with 10 to 20 users, with each user running 2000 iterations. With the number of open connections the load testing will make, I was pretty sure the original Linksys firmware would not be able to handle it, so I was curious on how the DD-WRT firmware would perform.

The results was very promising, after running the load testing for an hour, my network was still running smoothly, and I had no connectivity issues with surfing the internet. I was also, able to download bittorrent and watch streaming video at the same time without experience any latency. I checked the status page of the router and found that the router was experiencing very high load for over a long period of time, as well it had 94% active connections of the available 4096.

Flashing My Linksys WRT54GL Router

Vincent Kong — Mon, 02 Jul 2007 14:43:27 +0000

Occasionally, I have been having trouble surfing the internet when I’m using bittorrent at the same. In the past, all I had to do was reset the router by unplugging the power. Later, I followed some tips of optimizing my connections and restricted my global connection to under 200. This helped a lot and I haven’t need to reset my router anymore for a while.

For the past 2 weeks the connectivity issue has come back again and reseting the router no longer helps anymore. The only way I can resolve the issue is to power down the boardband modem until I get a new IP address assign to me when it restarts.

I decided to take some risk and install a 3rd party firmware for my router as they are often tuned for higher loads. The two most popular firmwares I found are:

Both are GNU/Linux based firmware for embedded devices. I decided to try out DD-WRT because it had a better web interface, as well, as of version v23 was completely rewritten and the Linux Kernel is based on the OpenWrt Kernel.

I flashed my router with the standard generic version of v23 SP2 which can be downloaded from their website. The actually flashing was relatively easy, I just did a firmware upgrade using web administration interface from the original Linksys firmware.

One issue I had, was that I wasn’t able to access the web administration interface for DD-WRT after the flashing. However, that was resolved when I hard reseted my router, unfortuntately all my preivous settings was gone after this, but it wasn’t too painful to set everything back up again.

Building a Server at Home

Vincent Kong — Tue, 08 May 2007 15:15:22 +0000

This is a high level overview of what I did to build my server at home.

Hardware for the Server

For my server I recycled an older desktop, which works well since most unix operating systems uses less resources than Microsoft Windows.

Hardware Specifications for My Server:

Model:	IBM NetVista 8307-51U
Processor:	Intel Pentium 4 1.8 GHz 512K L2 cache
Memory:	512 MB
Hard Disk:	40GB HD 7200 rpm
CD-ROM:	48X CD-ROM
Ethernet:	10/100
Video:	Integrated Intel 845G

Building the Server

I decided to build a LAMP (Linux, Apache, MySQL, PHP) platform for my server. For the Linux operating system, I chose Ubuntu because it was very easy to install, provided a lot of documentation online, as well as it had great community support.

Setting up the Network/Router

For the server I manually gave it a static local IP address 192.168.1.100. In my router I enabled port forwarding for ports 80 (for HTTP) and ports 22 (for SSH) to forward to 192.168.1.100.

Registering a Domain Name

To register for a domain name I use GoDaddy because they are currently the cheapest provider that I can find, and domain managing was through their web based interface which makes things really easy.

Setting up Dynamic DNS

My ISP provider provides me with a dynamic IP address, therefore I had to search for a DNS service that provided dynamic DNS support. I registered at ZoneEdit because it provides the service free for up to 5 domains. After successfully registering, ZoneEdit provided me with two name servers which I had to update my domain name to use through GoDaddy.

Setting up Dynamic DNS client

I use ddclient to update my dynamic DNS entries for ZoneEdit. The client is ran as a service which get executed every 5 minutes. When it awakes, it connects to my router and extracts the WAN IP address. If the address has changed then it’ll update my entry in ZoneEdit.

After I finish configuring everything I’m able to connect to my server using the domain name I registered at GoDaddy vincentkong.com. I can now then setup the rest of the services that I want to be available on my server. e.g. Apache, FTP, SSH, SMTP, etc.