If you are using vpopmail and qmail to host virtual domains, you can get a list of all the aliases in a domain by using valias. The syntax is
valias -s DOMAIN_YOU_WANT_TO_LIST_ALIASES
If you want to list the users (and NOT aliases) in a domain, you can use vuserinfo. The syntax is
vuserinfo -D DOMAIN_YOU_WANT_TO_LIST_USERS
I flew Lufthansa, on my recent trip to India and was very impressed by the hospitality and the services offered. One of the coolest service on the flights was “Wi-Fi” hotspots offering Internet service. While the service was a bit expensive at $10.00/hour, I tried it out just to satisfy my geeky urgings. It was a blast chatting with friends and telling them that I am doing it from 35000 feet in the air ;). For anyone wanting to try this, I would reccomend getting the “unlimited” access for the entire duration of the flight for $29.95. I would love to look at the technology behind this setup. I am sure they are using satellites for the Internet access. Just interesting how they make sure that the connection stays steady while the flight is moving, since satellite service is very dependent on “point-of-view” access to the satellite.
NMAP is an open source network scanning utility. It has tons of options and is a very powerful tool that every administrator needs to know about. Recently, we were checking if UDP port 88 was open on a certain server. NMAP to the resuce :)..
nmap -sU -p 88 DESTINATION_SERVER_IP did the trick. The “-sU” option forces nmap to only scan UDP ports and “-p” forces nmap to only scan the specified port.
Challenge: You are asked to update ~500 records on your DNS servers running Windows 2003 SP1.
Solution : Spend hours and hours updating the entries using the pretty MMC based GUI
or
use some creative scripting to do the work for you. Here is the recipe
1) Download the Windows Support Tools for SP1 from here. The support tools contain a useful utility called “dnscmd”. The tool allows one to add/update/delete entries for Windows DNS servers through a command line interface. DnsCmd /help returns the following
| Usage: DnsCmd []: IP address or host name — remote or local DNS server . — DNS server on local machine : /Info — Get server information /Config — Reset server or zone configuration /EnumZones — Enumerate zones /Statistics — Query/clear server statistics data /ClearCache — Clear DNS server cache /WriteBackFiles — Write back all zone or root-hint datafile(s) /StartScavenging — Initiates server scavenging /ResetListenAddresses — Set server IP address(es) to serve DNS requests /ResetForwarders — Set DNS servers to forward recursive queries to /ZoneInfo — View zone information /ZoneAdd — Create a new zone on the DNS server /ZoneDelete — Delete a zone from DNS server or DS /ZonePause — Pause a zone /ZoneResume — Resume a zone /ZoneReload — Reload zone from its database (file or DS) /ZoneWriteBack — Write back zone to file /ZoneRefresh — Force refresh of secondary zone from master /ZoneUpdateFromDs — Update a DS integrated zone by data from DS /ZonePrint — Display all records in the zone /ZoneResetType — Change zone type /ZoneResetSecondaries — Reset secondary\notify information for a zone /ZoneResetScavengeServers — Reset scavenging servers for a zone /ZoneResetMasters — Reset secondary zone’s master servers /ZoneExport — Export a zone to file /ZoneChangeDirectoryPartition — Move a zone to another directory partition /EnumRecords — Enumerate records at a name /RecordAdd — Create a record in zone or RootHints /RecordDelete — Delete a record from zone, RootHints or cache /NodeDelete — Delete all records at a name /AgeAllRecords — Force aging on node(s) in zone /EnumDirectoryPartitions — Enumerate directory partitions /DirectoryPartitionInfo — Get info on a directory partition /CreateDirectoryPartition — Create a directory partition /DeleteDirectoryPartition — Delete a directory partition /EnlistDirectoryPartition — Add DNS server to partition replication scope /UnenlistDirectoryPartition — Remove DNS server from replication scope /CreateBuiltinDirectoryPartitions — Create built-in partitions |
As you can see, there is ton of stuff you can do with this utility. I am mainly interested in the /RecordAdd function for this example.
2) Write a small perl script to massage your raw data into the form you want. In this case, I was given the hostname and the IP address in an excel spreadsheet. I exported the spreadsheet to a command delimited file and the following perl script finished the job for me
| #!/usr/bin/perl -w # use strict;my (@File, @Column, @HostID, @NetworkID, $Line); my $infile = ‘NetworkCore.csv’; my $outfile = ‘NetworkCore_Processed.txt’; open(READ,”$infile”) open(OUTPUT,”>$outfile”) foreach $Line(@File) |
Note : The DNS_SERVER, DOMAIN_TO_ADD and xxx.xxx.in-addr.arpa need to be replaced with your own values
3) Open a command prompt on the DNS server and copy and paste the contents of the file that the perl file spits out.. Did, I say that I love technology?? :)..
I have been maintaining my @kudithipudi.org address for some time now. I had all my E-mail from 1998 saved on my laptop until I had a hard drive disaster (ALWAYS BACKUP YOUR DATA), and lost all that E-mail. Ever since then, I have been trying to come up with a method to make my E-mail “crash” proof. I could have moved to using any of the popular free mail platforms (hotmail, yahoo, gmail etc.), but I didn’t want to loose the ability to send E-mail from my personal @kudithipudi.org address.
Google to the rescue – I was checking the settings on gmail the other day and noticed that I could setup a different E-mail address (which has to be verified) as my default “from address”. So I started forwarding E-mail from my domain to gmail. The problem now was to upload all the E-mail I have in Thunderbird up to gmail. That way, I would have all my E-mail in one single place and allow me to search through it. Google to the rescue again :), a query for “upload mail from thunderbird to gmail” returned this cool utility by Mark Lyon. It allows you to specify the source of your email and uploads the mail to your gmail account.
The next challenge was to find the directory/file where Thunderbird stores all the email. Google to the rescue again. You can get the location of the mail files from the account settings screen –> Local Folders in Thunderbird.
I am in E-mail bliss now. Use Gmail for all my messaging purposes. Next task would be to start using the Google Calendar.
Ran into an issue at work, where we had to reprocess all e-mails for a particular user on a Linux server. The email was stored in the standard mailbox format in /var/mail and all the e-mail was supposed to be sent to a different e-mail address. Here’s how we solved the issue
1) Use formail to split the mailbox into seperate messages and pipe it to sendmail. Command used was
formail -Y -n -s� sendmail -odq NAME_OF_USER < /var/mail/NAME_OF_USER
2) Force sendmail to process the queue and send the e-mail to the new address. Command used was
sendmail -v -qRNEW_EMAIL_ADDRESS
You can also edit the .forward file in the users home directory to forward e-mail to the new address and then you don’t have to specify the new e-mail address in the second command.
Link listing keyboard shortcuts (yes, they are still faster and more efficient 🙂 ) for Mozilla Firefox
http://www.mozilla.org/support/firefox/keyboard
Just discovered that “ctrl + w” closes a tab window :).
Quick post (more to come later on) on how to install/configure VMWare Server on Ubuntu
1) Install Ubuntu in “server” config
2) Install X-Windows on Ubuntu by using
“sudo apt-get install ubuntu-desktop”
3) install smbmount/mount to access windows shares
“sudo apt-get install smbfs”
NOTE : To map a windows share.. try the following
“sudo mount -t smbfs -o username=WINDOWS_USERNAME,password=WINDOWS_PASSWORD //WINDOWS_SERVER_NAME/c$ /tmp/FOLDER_TO_MOUNT”
4) Install make by
“sudo apt-get install make”
5) To install a smp capable kernel,
a.Search for smp kernel images by using
“sudo apt-cache search smp”
b. Install the appropriate smp kernel from the list. In my case, it was
“sudo apt-get install linux-amd64-k8-smp”
6) Install 3.4 version of GCC so that VMWare can compile the kernel modules
a. sudo apt-get install build-essential
b. Install the kernerl headers for your kernel. To do this, first get the Kernel version by
sudo uname -r
I got “2.6.12-10-amd64-k8-smp”
then get the kernel headers by
sudo apt-get install linux-headers-‘kernel version’, in my case, it would be
sudo apt-get install linux-headers-2.6.12-10-amd64-k8-smp
c. Install 3.4 version of GCC by
sudo apt-get install gcc-3.4
d. Install the right g++ version by
sudo apt-get install g++-3.4
7) Install xinetd
“sudo apt-get install xinetd“
One of my friends pointed me to www.zillow.com when he came to know that I was looking into buying a house. Zillow is a great resource for anyone looking to buy/sell property. I was very impressed by the data that Zillow collects and the way it is presented. I checked out the management team for Zillow out of curiosity and looks like it was started by ex-expedia folks.
Zillastic!! 🙂
