To add to the confusion, users using Airtel broadband and Reliance USB modem were able to browse the website. It was easy to blame Tata for this but the culprit (well, more or less) was the pfSense firewall.After struggling with Tata customer support, blaming them for this peculiar issue, the IT team of my client started troubleshooting. As a useful input, I was told that if the Tata broadband line was directly connected to a laptop, users using Tata Photon USB were able to connect to the laptop. This led me to suspect pfSense

To investigate this, what I did was as follows. I remote logged in to one of the user’s laptop who was using the Tata Photon USB modem. I ran a traceroute to the server.

The following image shows the output of the traceroute (tracert command running in a DOS terminal on Windows XP).

Traceroute from a Tata Photon USB to Tata Indicom Broadband

For security reasons, I have changed the actual hostname to abc.com and IP to 121.243.xxx.xxx in the above image.

Note the second last hop. It is a router (or whatever device) with an IP address 172.31.131.26! This seemed like a private IP address (more on this later).  This shows Tata is routing a connection, from a Tata Photon modem to a Tata Broadband, internally. So, for the pfSense firewall, the request is coming from a private IP (172.31.131.26 in this case).

With this finding in hand, I logged into the pfSense web interface and checked the firewall rules. But didn’t find anything suspicious or obstructing there.

The Solution
The solution was on the WAN page (Interfaces>WAN). While browsing this page, I spotted two options on this page namely Block Private Networks and

pfSense by default blocks private and reserved IP addresses

Block Bogon Networks.

Both settings were hinting at something to do with private IPs and were checked (on) by default. What worked was unchecking Block Bogon Network. After reading up on Wikipedia, I found that the IP 172.31.x is a reserved IP  but not defined for private networks in the RFC 1918. This is the reason why unchecking Block Private Networks  did not work.

Bottom line: If Tata is not able to talk to Tata and you are using pfSense firewall, goto Interfaces>WAN and uncheck Block Bogon Networks.

As of now Mango is in beta. The beta update is available to those with a developer account and pretty much limited to certain countries which does not include India. But my Dell Venue Pro bought in India is powered by Mango Beta now! It was earlier running official NoDo update (OS version: 7.0.7390). Following is how I updated my Dell Venue Pro without rooting it, unlocking it and without a developer account.

First, I must give all credit to the following two links and Google:

Link 1: http://windowsphonehacker.com/articles/get_the_mango_update_now._without_being_a_developer.-06-30-11
Link 2: http://www.redmondpie.com/how-to-install-windows-phone-7-mango-beta-update-on-any-wp7-phone-even-if-youre-not-a-developer/

While I followed these links to get Mango Beta up and running on my phone, the installation experience was not exactly as documented. Hence, I share my experience in place. I updated my Windows Phone using my laptop running Windows 7 Ultimate 64bit. The version of Zune software on my laptop was 4.7.1404.0.

Important note: Do not skip or say no to any question/prompt which asks you to backup your phone. More on this later.

First, I downloaded and installed Windows Phone Support Tool. The download URLs for 64bit and 32bit versions are given in Link 1 (refer to point 2, under the section “Updating to Mango”). I downloaded and installed the 64bit version.

Next, I downloaded mangoforall_0.2.zip. The download URL to this file can be found in Link 1 (refer to the third paragraph under the section titled ”Updating to Mango”).  I extracted the zipped file. This produced a directory called takesonetomango with four files namely prov.cab, readme.txt, restore.bat and Update.bat. While I think it wasn’t required, I extracted prov.cab (using WinZip) which produced a file named DeviceProvisioning.cab.pkg in the directory takesonetomango.

Connected my Dell Venue Pro to my laptop via USB. Double clicked on Update.bat. It started backing up my phone and created a directory named PreMangoState in C:\. After backup, it launched Zune. Unlike the instructions (in the readme.txt file), Zune did not prompt for any available update

I unplugged my phone, closed Zune, re-plugged my phone and double clicked on Update.bat. The Update.bat again started backing up. It prompted me whether to overwrite the files in C:\PreMangoState. I opted for All (overwrite all files). This time, the Update.bat did more than before. It rebooted my phone and my phone started updating! I felt moving closer to getting the Mango update.

After updating when my phone rebooted, I started checking my phone to spot any glimpse of Mango’s features, but found none. Then I checked the OS version (Settings>about>more information). Alas, the OS version remained the same as before (i.e. 7.0.7390).

I unplugged and replugged my phone. Zune launched. After a few seconds, my phone and Zune prompted me for an update! I started updating my phone via Zune. The update said something related to ISV (I did not note it down exactly due to all the anxiety). The phone rebooted and updated. After subsequent reboot, I again started checking for anything Mango-ish but was disappointed. Then I checked the OS version which was now updated to 7.0.7401.0. Some glimpse of progress!

I repeated the trick of unplugging and replugging the phone. And it worked!

Mango ISV Beta (version 7661)

I was again prompted for an update and this time the update clearly said “Welcome to the Windows Phone ”Mango” ISV Beta!” and “Your phone will be updated to version 7661″.

I followed the onscreen instructions. Note that it took a long time for this update to complete. After the reboot, the phone was stuck at the Dell logo for a long time. The subsequent screen showing Windows Phone logo also stayed for a longer time. This screen also showed “Not for resale” message in red, at the bottom.

I waited patiently and was rewarded with a successful Mango Beta update. I could see conversation thread in Email and  spotted Twitter under Settings>email+accounts>add an account – though it said “coming soon” . The OS version showed as 7661.WP7_5_Trial(mojobld).20110607-1657.

The entire process, starting right from the beginning, with all the backups, updates and anxiety took about a hour. What I’m trying to convey is, be patient and don’t unplug the phone during an update or stuck screen. You will see the fruit!

While it seemed the deed is done, but there was more to it. When I unplugged the phone and replugged it (in the hope to get another update ) , this time Zune prompted for an available update for Zune Software. But the update failed with an error message saying “can’t find the media for installation package ‘Zune WMDU Component’. It might be incomplete or corrupt”. I reinstalled Zune, it again prompted for an update and the same error showed up yet again.

That’s where Link 2 came handy. It suggested that I should download a beta version of Zune and provided the download URL (refer to the point 4 in the section “Here’s what you’ll need:” ). I disconnected the phone installed the beta version of Zune. Upon reconnecting the phone,  it started syncing again. With the Zune fixed, the first thing I did was to setup 24′s CTU ringtone (custom ringtone) on my Mango powered Dell Venue Pro

In the beginning, I wrote a note saying not to say no to any backup prompts. The reason for this is as follows. A phone updated with Mango Beta as per the above method may fail to update to Mango final release (as and when it arrives). Hence, it is utmost important to preserve the backup in C:\PreMangoState. As per the instructions in the links, the phone can be restored back to it’s last official update by running restore.bat (found in mangoforall_0.2.zip). I will try this out soon and update this post about success/issues in the restoring.

Update (July 21, 2011): I switched back to NoDo using restore.bat on 21st July. As I tweeted the steps to restore went a little haphazard. Hence I did not update this blog post. Nevertheless restore to NoDo works! I plan to again go back to Mango. Will update this blog post when I yet again switch back to NoDo with precise steps on restoring to NoDo.

Update (July 28, 2011): I’m now running Mango build 7712 (7.10.7712.60) on my Dell Venue Pro. This gives me the missing Twitter and Linkedin integration! How did I install it? Well, as I mentioned above, I had restored back to NoDo. Today I tried going back to Mango following the same steps mentioned in this blog post. And voila! the last update that got installed was Mango build 7712 instead of 7661

With reference to my comment:

Update (September 28, 2011): With reference to the following comment:

I’m back to NoDo (just to check if I can go back). Haven’t updated the blog post yet coz the downgrade steps went little haphazard for me. So I’m planning to again install Mango Beta, followed by a downgrade

and

the requirement to download Zune Beta

this time Zune prompted for an available update for Zune Software. But the update failed with an error message saying “can’t find the media for installation package ‘Zune WMDU Component’. It might be incomplete or corrupt”

I went back to Mango Beta. The good news is now Zune beta is no longer required. Zune will still prompt you for the update but will successfully update to version 4.8.2345.0 with which you will be able to sync your phone running Mango Beta. I found this a couple of weeks back. Sorry for the delayed sharing.  As of this writing I’m going back to NoDo hoping to get the official Mango update for my Dell Venue Pro. Will keep this post updated.

Update (September 30, 2011): Guys! Here is an exciting news! The moment I connected my phone via USB, to downgrade to NoDo, Zune prompted me for an update and I could update to Mango Final (OS version: 7.10.7720.68). I was tweeting while my phone was updating! You can find those tweets archived here.

Bottom line: my Dell Venue Pro running Mango Beta (OS version: 7.10.7712.60) got updated to Mango Final (OS version: 7.10.7720.68) without going back or downgrading to NoDo.

Prompt to update to Mango Final

Mango Beta Cleanup Update

Zimbra stores the E-mail users’ credentials in its built-in LDAP server. Hence it made sense to authenticate the login of other services or products like osTicket against Zimbra’s LDAP.

Following is a short tutorial on how I achieved it.First and foremost, ensure that the usernames in Zimbra and the usernames of Staff members in osTickets are the same. Thankfully osTickets allows to edit usernames of the staff members. Most importantly, do rename or match the admin username in osTickets with a username in Zimbra.

Note that, you must create users under Staff members in osTickets. The users will not be created automatically through LDAP, as you may have seen with other LDAP integrations. Since osTickets mandates to setup a password for the staff members, type in any password. This password will not be used for login.

Authenticating osTicket with Zimbra’s LDAP is a matter of adding and modifying a few lines in a file. Thanks to adLDAP, an easy to use PHP library for LDAP. Download adLDAP 3.3.2 from http://prdownloads.sourceforge.net/adldap/adLDAP_3.3.2.zip?download. Unzip the zipped archive. Copy the resulting directory named adLDAP to <osTicket-installation-dir>/include/ directory.

Next, open the file named class.staff.php, found in <osTicket-installation-dir>/include, in a text editor. Add the following line towards the beginning of the file, just after <?php

include("adLDAP/adLDAP.php");

Next, append the following to the end of the file:

<?php

function zimbraAuth($username,$password){
$options = array("domain_controllers"=>array("<zimbra-server-name-or-IP>"),
          "ad_username"=>"uid=admin",
          "ad_password"=>""<zimbra-password>"",
          "account_suffix"=>",ou=people,dc=domain,dc=com"
          );

$auth=false;

try{
  $ldap = new adLDAP($options);
  $auth = $ldap->authenticate("uid=$username",$password);
  }
catch(adLDAPException $e){
  $auth=false;
  }
return $auth;
}

?>

In the above code, replace <zimbra-server-name-or-IP> with the DNS name or IP address of the server running Zimbra. Replace <zimbra-password> with the password of Zimbra’s admin user. Set the account_prefix as per Zimbra’s domain name. For example, if Zimbra is setup for the domain abc.com, replace:

“account_suffix”=>”,ou=people,dc=domain,dc=com”

with:

“account_suffix”=>”,ou=people,dc=abc,dc=com”

Last, find the line which reads:

return (strlen($this->passwd) && strcmp($this->passwd, MD5($password))==0) ?(TRUE):(FALSE);

Comment out the line, by prefixing //, as follows:

//return (strlen($this->passwd) && strcmp($this->passwd, MD5($password))==0) ?(TRUE):(FALSE);

Add the following line just after the above mentioned line:

return (strlen($this->passwd) && zimbraAuth($this->username,$password))?(TRUE):(FALSE);

Save the file. Now you should be able to login into osTicket’s control panel using Zimbra password for the corresponding osTicket user. While, this blog post is specific to authentication against Zimbra’s LDAP,  there is no stopping you from authenticating against any LDAP server like OpenLDAP or Microsoft Active Directory. All you have to do is to tinker the following lines as per your LDAP setup:

$options = array("domain_controllers"=>array("<zimbra-server-name-or-IP>"),
          "ad_username"=>"uid=admin",
          "ad_password"=>""<zimbra-password>"",
          "account_suffix"=>",ou=people,dc=domain,dc=com"
          );

In fact, tethering has often come to my rescue where most other ways to connect to the Internet have failed. I blame it on the lack of their availability and/or price. Hence I aptly demand tethering from every phone I own or use. But my latest  phone, a Dell Venue Pro (powered by Windows Phone 7), does not support tethering out of the box.

Googling reveals a hack which is repeated across the Web. But the hack never worked on my Dell Venue Pro. The issue was, the hack instructs switching to Composite mode via an option called Service Center. But on my phone I could not spot the Service Center. I suspect it could be that Dell chose to hide the Service Center option in its phones sold in India. Fortunately, I found a trick which reveals the Service Center.  Thanks to these couple of hacks, I now enjoy USB tethering with my Dell Venue Pro, on my laptop running Windows 7 64bit. Following is how I tethered my Dell Venue Pro bought in India.

1. Follow the instructions found here (original link) or here (better explained).
2. As explained above, if you don’t see the Service Center under EM, refer to this interesting trick.
3. Following are the Extra Initialization Command, for a few phone service providers in India, that I tried out. The dial-up number *99*# and a blank username and password worked for me for all these service providers.
   • Vodafone:
     AT+CGDCONT=1,”IP”,”portalnmms”
     or
     AT+CGDCONT=1,”IP”,”blackberry.net”
   • Airtel:
     AT+CGDCONT=1,”IP”,”airtelgprs.com”
   • MTNL 3G:
     AT+CGDCONT=1,”IP”,”gprsmtnldel”
     

I have not included the entire step-by-step instructions to tether a Dell Venue Pro because I want to give full credit to the original websites that posted the much-needed hacks. Having said that, in case you have any queries you can always shoot a comment at me

Note: If you want to sync with Zune Software, you will have to turn off Composite mode and switch back to Zune mode. This can be done by going to the Service Center (as explained in the links above) and clicking on the Zune button.

Happy Tethering!!!

1  30  *  *  *  /usr/bin/php -q /opt/script.php

Instead, I prefer a crisper line as:

1  30  *  *  *  /opt/script.php

The latter is obviously neater and readable. To prepare a PHP script to execute just by the filename, you need to do two things:

1. Add a line to the path to the PHP interpreter at the top of the script. For example:

   #!/usr/bin/php -q
   <?php
   // PHP code
   ?>

2. Make the script executable as:

   chmod + script.php

Before inserting it in Cron it is always a good idea to test the script by executing it manually as:

/opt/script.php

What always worked for me, failed on me this time with an error saying: Extension /opt/script.php not present. What will you do when you get an informative error (being sarcastic) like this? I too had no clue.I checked the path of the PHP interpreter, double checked the permissions and also found other PHP files to be working. The script worked when served via a Web Server (Apache). What added to the confusion was, the same script worked when executed as follows:

/usr/bin/php -q /opt/script.php

I could have wasted hours in troubleshooting this if it hadn’t clicked to my mind that the client who sent me this script uses Windows. This means, this script would have been written in one the Windows text editors. Going by experience, case insensitivity and newline characters is the root to most problems with script which are written in Windows and run on Linux. A quick check did not reveal any case related issue.

To fix the second possible problem, I used dos2unix – a handy commandline tool to convert Windows based text files into Linux files (more on this later).

dos2unix /opt/script.php

And voila! this fixed the problem. I was then able to execute the script as /opt/script.php and also scheduling it via Cron worked perfectly.

If you ask me, how exactly did Windows newline characters would have messed up the script to result into this cryptic error (Extension script.php not present), I don’t have an answer. But going by the above fix, it was definitely Windows newline characters which were causing the problem.

A note about Windows and Linux newline character: Windows uses \r\n as the new line or next line characters. \r is called the carriage return character and \n is called the line feed character. Whereas in Linux, \n (line feed) is the newline character. The command line tool called dos2unix replaces all the \r\n (carriage return and line feed pair) to \n (line feed) in a script or text file.

On the other hand, I’m at war with issues on the phone due to lack of my familiarity with a Windows Phone. After all, I had been using Android for almost two years. One issue that bothered me the most was, I could not dial toll free numbers in India using my Dell Venue Pro.For example, 1800-425-4026 is the toll free number for Dell India. When I dial this number on my Dell Venue Pro, a + (plus) is automatically prefixed to the number. Hence the number becomes +18004254026. On the phone dialer it shows up nicely formatted as +1 (800) 425-4026. This means it actually dials a U.S. number (+1 is the country code for United States). So forget toll free, I’m accidently dialing an international number for which I will be charged!

The crux of the matter is I was not able to dial any toll free numbers in India. What’s more, I’m was not able to call Dell using a Dell. For those who have seen the Hindi movie Karthik calling Karthik, the situation here was  ”Karthik not able to call Karthik”

So where did Dell screw up? Actually it is not Dell, it is Windows Phone 7. Seems the phone is tailored better for the U.S. customers than for Indian customers. But Dell must also not be forgiven. If they are launching a phone in India, they should have customized the bare bones for India. At the least they should have ensured that a Dell should be able to call Dell! After all, how would we call the toll free Dell support number(s) for any needed assistance for our phone.

Thankfully, the solution to the above is simple. The culprit is something called International Assist, found in the phone dialer’s settings. International Assist is defined as “Turning on this feature will help automatically correct some common mistakes while dialing internationally or dialing while abroad”. So it is the International Assist which decides that dialing a toll free number which starts with a 1 is a mistake and it corrects it by prefixing a +. And the worst part is, International Assist is turned “On” by default.

The Solution
To turn off International Assist, click on the Phone Tile or launch Phone from the list of applications. Tap on “…” on the bottom right. Select “call settings”. On Settings, turn off International Assist by tapping on the Toggle Switch. Now, you will be able to dial to toll free numbers in India and my Dell is able to call Dell

D-Link DWA-525 Wireless N 150 Desktop Adapter

My new “desktop grade server machine” at home has a 802.11n wireless PCI adapter namely D-LINK DWA-525 Wireless N 150 Desktop Adapter.  An adapter like this plugs into one of the PCI slots and connects to a wireless or Wi-Fi network. This helps to keep the machine anywhere in the house and not necessarily near a router or Ethernet port.

On my desktop, I did a minimal or base installation of Fedora 14 Linux. Fedora was not able to recognize the wireless adapter and hence could not connect to the Wi-Fi router at my home. But with some efforts, I was able to make the adapter work on Fedora 14. Additionally, I was also able to configure the wireless adapter from the command line. What follows is a crisp tutorial with the required steps to setup DIR-615 PCI adapter on Linux.

The following steps worked on a fresh installation of Fedora 14. While the steps mentioned are specific to Fedora 14 , they should work for other flavors of Linux with minor changes. For example, while the method of installing GCC (the C language compiler) may differ, installation of the drivers for the wireless adapter should work as mentioned.

Identify your Wireless adapter
Besides checking out the box and the manual of the wireless adapter, there is another way to identify it. Issue the following command:

lspci | grep RaLink

If the output contains something as follows:

Network controller: RaLink Device 3060

then this blog post is for you But the same steps may work for a few other models (as explained in the section Download the drivers).

Install the prerequisites
You will need to install gcc (C compiler) and kernel sources. On Fedora, they can be installed as follows:

yum install gcc
yum install kernel-devel-`uname -r`

Download the drivers
Browse to the URL http://www.ralinktech.com/support.php?s=2. Click on the link labeled RT3062PCI/mPCI/CB/PCIe(RT3060/RT3062/RT3562/RT3592). Note the label. Besides 3060, it contains other model numbers too. Hence if the lspci command (see above) gives a different (from 3060) number, this blog post may still work for you.

On the subsequent page, type in your name and e-mail and click on the Accept button. This will download a file named DPO_RT3562_3592_3062_LinuxSTA_V2.4.1.1_20101217.tgz. In my case, I downloaded the drivers on my laptop and uploaded it on my desktop machine via SSH. The following steps should be executed on the machine with the wireless PCI adapter. Login as root.

Install the drivers
Extract the downloaded file as:

tar -zxvf DPO_RT3562_3592_3062_LinuxSTA_V2.4.1.1_20101217.tgz

This will produce a directory named DPO_RT3562_3592_3062_LinuxSTA_V2.4.1.1_20101217. Open the file named config.mk, found in the directory DPO_RT3562_3592_3062_LinuxSTA_V2.4.1.1_20101217/os/linux/, in a text editor and modify the line:

HAS_WPA_SUPPLICANT=n

to

HAS_WPA_SUPPLICANT=y

Also change the line which says:

HAS_NATIVE_WPA_SUPPLICANT_SUPPORT=n

to:

HAS_NATIVE_WPA_SUPPLICANT_SUPPORT=y

Save the file. Next, change (cd) to the directory DPO_RT3562_3592_3062_LinuxSTA_V2.4.1.1_20101217 and issue the following commands:

make
make install

Reboot and voila! The wireless adapter should start working. You should be able to connect to your WiFi router or access point using NetwokManager in GNOME or KDE. In my case, I connected via the command line utility of NetworkManager called cnetworkmanager (as explained in the next section)

Connect to WiFi from the command line
My WiFi router is configured to use WPA or WPA2 authentication as shown in the screenshot below:

WPA settings on D-Link DIR-615 Wireless N Router

Install cnetworkmanager as:

yum install cnetworkmanager

To connect to a wireless router using WPA, append the following lines to the file named rc.local found in /etc directory:

sleep 5
cnetworkmanager -C <SSID>  --wpa-pass="<WPA-Password>" &

In the second line, substitute <SSID> with the SSID of your wireless router. Substitute “<WPA-Password>” with the password that you have specified in your router for WPA/WPA authentication. For example:

cnetworkmanager -C SHEKHAR --wpa-pass="secret123" &

Upon a reboot, the machine should automatically connect to your wireless router. That’s all folks!

I required the TV, keyboard and DVD drive only for the one time installation of the operating system. Post the installation, I access the machine only across the network – via SSH (Secure SHell) or a web browser.

But I decided against the easy way of installation using my TV and keyboard. Instead, I challenged myself to install Fedora 14 without using a monitor, keyboard/mouse and DVD drive on the server.

vncviewer showing Fedora 14 installation across the network

In a nutshell, such an installation can be achieved via PXE boot (a.k.a. network boot) wherein the operating system is installed across the network. The installation media itself can reside on any other machine on the network. What’s more, you can even interact with the graphical interface of the installation on any networked machine.

Note that while most modern desktops and servers have network booting, at times, you may need to enable it from the BIOS. This requires a monitor and keyboard defeating the very fun. In my case, network booting was enabled by default.

At the end of this exercise, I have an up and running Fedora 14 machine installed and configured completely across the network. Following is a jot down of how did I carry out this kind of installation.

As said above, you will need another machine connected to your network or your router.  In my case, I configured my laptop running Fedora 13 to serve the installation of Fedora 14 on my home server.

The installation and configuration mentioned below are specific to Fedora 13. But most steps, especially the configuration should apply to other flavors of Linux. The overall steps are as follows:

1. Configure the network (on the router and laptop).
2. Install the services on the laptop to:
   • Assign IP to the home server during the network boot
   • Serve the required files to the home server to boot and start the installation
   • Serve the packages to be installed
   • Interact with the graphical installer for disk partitioning, package selection etc.
3. Configure the services
4. Start the services
5. Switch on the target machine/server
6. Wait for the graphical installer to popup on the laptop, follow the onscreen instructions and ta-da!

Configure the network
At home, I’m on a network with IP 192.168.0.x. This means, machines at my home will have IP addresses like 192.168.0.2, 192.168.0.3 and so on.

First and foremost step is to stop any DHCP service, which provides dynamic IPs to machine. This is because the laptop will act as the DHCP server (as explained later). In my case, a D-Link DIR-615 router (with IP 192.168.0.1) is serving dynamic IPs. I logged into the router using a web browser and disabled DHCP by unchecking Enable DHCP Server (found under Setup>Network Settings).

Since DHCP is disabled, setup a static IP address for the laptop. This can be done via a Linux command line or console using the following command:

ifconfig eth0 192.168.0.2

To save yourself from added troubleshooting, disable any running Firewall and SELinux as follows:

service iptables stop

SELinux was already disabled on my laptop. For more on disabling SELinux refer to http://www.crypt.gen.nz/selinux/disable_selinux.html

Install the services
Install the required services as follows:

 yum install dhcp syslinux tftp-server httpd tigervnc

dhcp is the DHCP server which will serve dynamic IP to the server during PXE boot. syslinux provides the files required for booting. tftp-server (TFTP Server) will serve the boot files (provided by syslinux) and the kernel for the server to boot and start the installation. httpd (Apache Web Server) provides the Fedora 14 packages to be installed. tigervnc (TigerVNC) will be used to display the graphical installer on the laptop.

Configure the services: DHCP
To configure DHCP, open the file named dhcpd.conf found in the directory /etc/dhcp and modify it as follows:

subnet 192.168.0.0 netmask 255.255.255.0{
 range 192.168.0.10 192.168.0.20;
}
allow bootp;
filename "pxelinux.0";

Save the file.

Configure the services: TFTP Server
In a text editor, open the file named tftp found in /etc/xinetd.d and change the line:

server_args = -s /var/lib/tftpboot

to:

server_args = -s /var/lib/tftpboot -v -v -v

Appending “-v -v -v” will provide more information about the TFTP Server in /var/log/messages file which useful for troubleshooting. Next, change the line:

disable = yes

to:

disable = no

After the above modifications, the tftp file will look as follows:

# default: off
# description: The tftp server serves files using the trivial file transfer \
#	protocol.  The tftp protocol is often used to boot diskless \
#	workstations, download configuration files to network-aware printers, \
#	and to start the installation process for some operating systems.
service tftp
{
	socket_type		= dgram
	protocol		= udp
	wait			= yes
	user			= root
	server			= /usr/sbin/in.tftpd
	server_args		= -s /var/lib/tftpboot -v -v -v
	disable			= no
	per_source		= 11
	cps			= 100 2
	flags			= IPv4
}

Save the file.

Next, copy the files named chain.c32, mboot.c32, memdisk, menu.c32 and pxelinux.0 found in the directory /usr/share/syslinux/ to /var/lib/tftpboot directory:

cd /usr/share/syslinux
cp chain.c32 mboot.c32 memdisk menu.c32 pxelinux.0 /var/lib/tftpboot

Create a directory named pxelinux.cfg (yes, it is a directory with .cfg suffix) under /var/lib/tftpboot. Under the directory /var/lib/tftpboot/pxelinux.cfg, create a file named default with the following content:

default Fedora 14
timeout 0

MENU TITLE PXE Menu

LABEL Fedora 14
        KERNEL images/fedora/14/vmlinuz
	APPEND initrd=images/fedora/14/initrd.img lang=en_US keymap=us vnc vncconnect=192.168.0.2 ip=dhcp method=http://192.168.0.2/fedora/14/

Here the IP address 192.168.0.2 is the IP address of my laptop (as setup in the section Configure the network)

Create a directory tree images/fedora/14 under /var/lib/tftpboot:

mkdir -p /var/lib/tftpboot/images/fedora/14

We also need to copy two files from the Fedora 14 CD/DVD into this directory. This is explained in the next section.

Configure the services: Apache Web Server
As explained above, Apache Web Server will serve the packages to be installed. For this, we will download and mount Fedora CD/DVD under the directory /var/www/html (the default document root of the web server). Create a directory tree named fedora/14 under /var/www/html as:

mkdir -p /var/www/html/fedora/14

Next, download Fedora 14 DVD or CD ISO from http://fedoraproject.org/en/get-fedora-all. I wanted to do only a base install of Fedora 14 on the server. For this only the first CD of Fedora is required. So I downloaded Fedora-14-x86_64-disc1.iso from here.

Mount the downloaded DVD/CD ISO as:

mount -t auto -o loop <path-to-downloaded-iso> /var/www/html/fedora/14

In my case:

mount -t auto -o loop /home/shekhar/Downloads/Fedora-14-x86_64-disc1.iso /var/www/html/fedora/14

Copy the files named initrd.img and vmlinuz found in the directory /var/www/html/fedora/14/images/pxeboot to /var/lib/tftpboot/images/fedora/14.

Start the services
Next, open a Linux terminal or console window and start the services as follows:

service dhcpd restart
service xinetd restart
service httpd restart
vncviewer --listen

Connect the server to the network/router and switch it on. Within a minute you should be able to see the graphical installer on your machine (laptop in my case). Follow the onscreen instructions and you should end up with a successful Fedora 14 installation on the server.

Note that while we didn’t attach a monitor and keyboard for the installation, we didn’t even burn a CD/DVD! We let Apache serve the packages via the mounted ISO.  Plus, with Kickstart you can even have an unattended and automatic installation without interacting with the graphical installer.

PS: Once the installation is done, don’t forget to stop the DHCP server on your machine (service dhcpd stop) and start the DHCP service on your router.

In my case, the issue sprung up on the night of 25th October. I switched on my Xbox after a long time, updated it (as prompted) and started playing a game. After a few minutes of playing, Xbox hung, all of a sudden. I rebooted the console. This time it hung immediately during the welcome animation. I did not miss to notice 3 Red Lights flashing on the front of the XBox. Red means something wrong, 3 Reds mean something screwed up.

3 Flashing Red Lights Issue. Source: http://support.xbox.com

The nightmare was short lived. Thanks to the excellent Xbox support service in India. By the end of the 6th day, I owned a replaced, brand new, console. Before getting into the interesting story of the entire support experience, following is my suggestion on what you should do if you are facing the 3 flashing red lights issue with your Xbox.

1. Goto http://support.xbox.com/hi-in/pages/xbox-360/troubleshoot/flashinglights.aspx. Click on the Articles tab. Scroll down to the section Three flashing red lights
2. Follow the steps mentioned before submitting a service request.
3. To register a service request, goto https://myservice.xbox.com/en-in/Pages/Welcome.aspx and click on Start a repair request. Follow the instructions which will result in an E-mail with a Service Request Number.
4. Call  the Xbox support (http://support.xbox.com/hi-in/pages/call-us.aspx) immediately with the Service Request Number. After speaking to Xbox support, it may happen that you are assigned a new Service Request Number and the process of replacing your console speeds up.
5. The stated procedure is that the service center will courier you the replacement. But, when you get a call from the service center, ask them if you can pick up the console from the service center. If this works out, you may get your console exchanged in less in than 10 minutes – as it happened to me.

Note that, you can avail the support only when your Xbox is not tampered or modded. Also the above mentioned suggestion and the following story is based out of my personal experience and may vary across locations – I stay in New Delhi, India.

What follows is the story of what I went through to get my Xbox console replaced for the 3 Red Rings of Death.

Day 1: When my Xbox died
This was the night of 25th October. I switched on my Xbox after a long time, updated it (as prompted) and started playing a game. After a few minutes of playing, Xbox hung, all of a sudden. I rebooted the console. This time it hung immediately during the welcome animation. I could see 3 red lights flashing around the power button.

Googling around and reading information like this assured me that this is most likely a hardware problem. First, I went to the XBox support site and obediently followed the instructions like tightening up the power cables. This did not help. I did not have an alternate power outlet to try out the suggestion of changing the outlet.  My Xbox’s warranty had already expired. But googling around hinted that Microsoft offers a free replacement for 3 years for this specific issue of  3 red rings. So I clicked on “Start a repair request” and followed the onscreen instructions which prompted me to login using my Windows Live/Hotmail credentials and asked for my console’s serial number.

Once done, I received a detailed E-mail on the procedure to replace my console. The e-mail had my console number and a service request number. The E-mail also stated that “A service agent will come to your doorstep and exchange your non-working console for a working console” and “If you have not received a call from our service center after two days, please contact us by using the following contact information.” How cool it is. I was thrilled to read about this kind of quick and “at the doorstep” service. But things didn’t turn up as expected.

Day 2, Day3: The Wait Period
As suggested in the E-mail, I waited for the next two days expecting a call from the service center. But did not receive any call.

Day 4: 1 Month to Replace the Console?
I called the Xbox support at 1800-11-1100. After giving my service request number, the support person said that he will have to cancel this request and place a new request. Upon asking for the reason, he kind of implied that this kind of service (console getting replaced at doorstep) is no longer offered. I didn’t question him much on this. Once okayed, I got a new E-mail with a new service request number. But I was so heart broken to read the procedure mentioned in this E-mail. The E-mail instructed the following:

1. Wait for the shipping box: A shipping box for your Xbox 360 console is being sent to you and should arrive in 5 to 6 business days. Once the box arrives, you can prepare your console for shipping.
2. Prepare your console for shipping: Only send us your console. Please remove the hard drive, accessories, and discs before packing your console for shipping.
3. Pack and ship us your console: After you send the console to us for repair, you will receive a console within 2-3 weeks.

So if I add up the estimated time for the shipping box to arrive and the time taken to repair/replace the console, it was about a month. Also as said in step 3 above, Xbox service was hinting at a repair and not replacement.

Day 5: Glimpse of a Better Service
The very next day, in the morning, I got a call from the Xbox support. I told the person on phone that I’m waiting for shipping box. He asked me if I could go to the service center with my Xbox. The service center was about 30 kilometers away from my place. I promptly agreed. And there came the surprise, the service center person told me that at the service center I will immediately get a new console, on the spot. I was eager to visit the service center the same day, but due to some work, I postponed it for the next day.

Day 6: A Brand New Xbox
30th October 2010: I reached the service center at about 10:35 hrs and I was out from there by 1045 hrs, with a brand new console! Hail to Xbox support service!

DO NOT FORGET TO REMOVE THE HARD DRIVE

Remove the Hard Disk before giving your Xbox for replacement. Source: http://support.microsoft.com

While this was clearly stated in the E-mail from Xbox support, I did not read the instructions properly. I did not remove the hard drive from my Xbox console before giving it for replacement. I plugged in the new console on the night of 31st October. The console  reported about “No storage devices found”. Here’s where Xbox support, this time on Twitter, came to help. After a hour long exchange of tweets with @xboxsupport, I realized my mistake.

The next day I called up the support center person. Despite being a Sunday, he took my call and assured me saying that he will remove the hard drive and I can collect it back from the service center. On Monday morning, I collected the hard drive back and the evening I plugged it back into the replaced console. Rock-n-Roll!

Bottom line: Xbox support service in India rocks. Plus Xbox Support is very active and helpful on Twitter.

Now the issue was, many JPEG images, especially the larger ones, loaded up only partially in a Web browser (both Internet Explorer and Firefox). What made them load fully was pressing CTRL+R or clicking on Refresh/Reload several times. Bandwidth wasn’t an issue here, since this problem occurred even when browsing the JPEGs from the local network.

At first, I doubted that it could be an issue with the way the JPEGs are produced, something related to the progressive rendering et al. But then I came across an instance (too involved to explain it here) which proved me wrong.

Testing the case further, I found that the JPEGs load absolutely fine in the Web browser, when opened up via File>Open – instead of hitting the Web Server. This made me turn my eyes onto the Apache Web server. Googling around and reading the comments in the Apache configuration file gave a few hints. With some hit-n-trial, the solution that worked for me is as follows:

• Login as root
• Open the httpd.conf file (the configuration file of Apache Web server) in a text editor (like vi). On RedHat/Fedora/CentOS Linux, this file can be found in the directory /etc/httpd/conf
• Append the following line to the end of the file:

  EnableSendfile off
  

• Save the file.
• Reload or restart the web server. On a RedHat/Fedora/CentOS Linux the command ‘service httpd reload’ can be used for the same.

The EnableSendFile directive in Apache is documented as: “Control whether the sendfile kernel support is used to deliver files (assuming that the OS supports it). The default is on; turn this off if you serve from NFS-mounted filesystems.”

What caught my attention was “turn this off if you serve from NFS-mounted filesystems”. But, in my case, the JPEG files were mounted via CIFS and not NFS. But reading more about the EnableSendFile directive at http://httpd.apache.org/docs/2.2/mod/core.html#enablesendfile, reveals the it affects even SMB (and hence CIFS) or any other network mounted files. Following is the snippet from the document:

With a network-mounted DocumentRoot (e.g., NFS or SMB), the kernel may be unable to serve the network file through its own cache.

Also, I guess, this solution is not specific to JPEG files. The above mentioned issue and the solution should be applicable to other file types too, which are served from a network mounted drive.