Sunday, September 26, 2010

IE9 Beta Release

Peoples are more familiar of the concept of Beta Release in the open-source world. Idea was - it can be tested by scores of real-world users, each using their own computer systems with varieties of Hardware and Software. And the conflict with the various programs or hardware gets reported real fast. I am not sure from when exactly Microsoft started doing that; anyway, Microsoft did a Open(!) Beta release of IE9 on last Wednesday.

I was actually very excited to see this release as it was much hyped on 'Chakra' javascript engine(uses multicore and hence faster than other java script engines), faster browsing, more web surface and some other features along with HTML5 and CSS3 support. Another interesting development is that IE9 will now support SVG, which it has shunned for years. This is a really huge leap forward. Does it mean that Microsoft wants to put their foot forward along with the web standard rather than its own?

I was always excited to see - when Microsoft will get their browser right, so that web developers can create better sites!! I downloaded and and installed it on my Windows7 PC, it installed fine. But whenever I tried to open it up, it displays this message saying " Internet Explorer has stopped working , windows is checking for a solution to the problem" and it goes in an infinite loop because of the tab recovery feature. I couldn’t even give it a spin because it stopped working automatically. And If my stats ae right, it crashed 5 times in that span of 10-15 mins.

I still have one of my desktop which runs XP, but unfortunately, IE9 is not available for Windows XP. (I guess there won’t be), probably because of the security model and XP now nearly 10 years old! Another reason is that graphical core on Windows XP works in a different way, so IE9 hardware acceleration just cannot work there.

Late Review; sheer disappointment!! But yeah, I look forward to see these catchy features when Microsoft releases it finally for the public as a stable product.

Ah! Happily back to my favorite Mozilla browser again!!

-DEBAJIT


Friday, September 24, 2010

SSL cert on windows IIS


I was taken aback yesterday when I got this request. Good to know stuff for *nix guys, never know when you get a similar request. :-)

1) Download new Trusted Root Cert.

2) Move the new certificate mynew.crt to server that needs update

Caution:

You can NOT simply double click on the cert once it is on the server as that will install the cert to the currently logged in users Trusted Authorities. Use the instructions below to install the cert for the entire server


  • Log into the server
  • Start run, type mmc on run line and hit enter
  • In the MMC Console click on File -> Add/Remove Snap-In
  • In Add/Remove Snap in window click on Add
  • In Add Standalone Snap-in window select Certificates and click on Add
  • In the Certificates snap-in window make sure Computer Account is selected and click on Next
  • In the select Computer window verify Local computer is selected and click on Finish, that window will close
  • Back in the Add Standalone Snap-in window click on Close, that window will close
  • Back in the Add/Remove Snap-in window click on Ok
  • In the MMC console left pane, expand Certificates
  • Expand Trusted Root Certification Authorities
  • Right click on Certificates and select All Tasks -> Import…
  • In the Certificate Import Wizard click on Next
  • At the next screen click on browse and browse to the location of mynew.crt and click on Next
  • Verify that it will be installing the cert to Trusted Root Certification Authorities and click on Next
  • Verify info on screen and click on Finish
  • From a command prompt, recycle IIS by running “iisreset /restart”
  • After IIS has been cycled test the web site
Cheers!
DK

Wednesday, September 22, 2010

Simple File Sharing with Python SimpleHTTPServer

Have you ever come across a situation where you quickly need to share a file and you lack that quick expertise to setup FTP/Apache or Websphere. Python has this in built SimpleHTTPServer which can solve this and help you share any file in seconds.

For ex. you want to share some files in /appsData.

[root@DebaTestBox debu]# cd /appsData
[root@DebaTestBox appsData]# python -m SimpleHTTPServer 18000 &

Now you can see that your SimpleHTTPServer is running on port 18000

[root@DebaTestBox appsData]# netstat -lntp | grep 18000
Active Internet connections (only servers)
tcp 0 0 0.0.0.0:18000 0.0.0.0:* LISTEN 16889/python

[root@DebaTestBox appsData]# ps -ef | grep HTTP
root 16889 16861 0 05:48 pts/0 00:00:00 python -m SimpleHTTPServer 18000


Now go to any web browser and try to see the files as below:

http://YourServeripAddress:18000

Yay!! That's it !!!! You are now sharing your files without setting up a dedicated weblogic or apache or any FTP Server and it did not really ask for any prior hardcore knowledge of system administration.

Network ACL check whether a port is open or not:

This can even be used to test whether a port is open between two servers when the respective services on them has NOT yet been started. Run this server on the port which you want to check on the first server and do a telnet from the other box. This is one of way how you can test a Network ACL port open or not, probably in less than 10 sec ! Yeah? Enjoy!

Cheers!
DK

Tuesday, September 21, 2010

Best Free Online Scanner

You can keep a bookmark of the below free online scanners -

McAfee’s Freescan,
Trendmicro’s HouseCall, and
Symantec’s Security Check.

I have also come across Eset's scanners as well. Eset is a trusted name; their antivirus solutions have been a gold standard in security for many years now.


Enjoy!
DK

Sunday, September 19, 2010

See last modified File in UNIX

I strongly suggest installing a File Integrity checker like Tripwire on your server. Even if you don't have that we can always use 'stat' command of UNIX to see these stats on suspected file or file in question.

But there is less popular version of find command which can quickly check and list the set of files ordered by last modified time , that too in a matter of seconds. Not "what Got Changed" though! Just try it out :-)

find /etc -type f -printf "%T+ %p \n" | sort -n

-Cheers!
DK

Check a bash script without executing

This is really essential sometime, we want to check the syntax and validate our script rather then running it upfront.

Available Options:

Debugging Options set -o Option Command-line Option Action
noexec -n Don't run commands; check for syntax errors only
verbose -v Echo commands before running them
xtrace -x Echo commands after command-line processing


Example:

$bash -n myscript.sh
$/bin/sh -nv myscript.sh

Enjoy!!!
DEBU

Skip Linux History

Have you ever felt... you want to quit your bash session without saving your history? I am not sure for what good reason, but yes there are ways -

$ kill -9 $$

Here, $$ is the pid of the current bash instance.
Or,

$unset SAVEFILE;unset HISTFILE;

This way you can skipfast from being you session recorded in Bash History!!

PS. But I have usually seen this behavior specially amongst Freshers, trying to hide their mistakes out of panic, which is wrong. You should NOT hide it, rather report them actively. Error is inevitable in every sphere of human activity. Just we need to be sure about what we do and a bit careful while doing the same, that's it !!

Enjoy!
DK

Wednesday, September 15, 2010

My Favorite netcat(nc) combinations

Netcat(nc) has always been referred to as the legendary Swiss Army Knife of Networking. It is a single binary, which takes up about some KB of space of space on your disk, but yet so handy!! Below are some of my netcat favorite I use time to time.

See which ports are open on a particular server.

#nc -v -w 2 -z 172.16.80.70 1-65535

Checking disk status of a set of server mentioned in a text file wslist.txt


#for i in `cat wslist.txt`; do echo $i; ssh -q $i df -h|grep /data$|awk '{ if($5>=90) {print $5 "->Disk Danger"} else { print "Disk OK"}}' ; done

Check if port 22 is open a list of server mentioned in wslist.txt

#for i in `cat wslist.txt`; do nc -v -w 1 -z $i 22 ; done

Transfer a file from Server A to Server B on a specified port.

Server B
nc -l 1337 > dk.txt

Server A
nc 172.16.80.70 1337 <>

[rick@TestBox ~]# nc -l 1337
Hey Debu,did you know we can chat on the console like this?
@Rick, yeah! It's so cool man..


[debu@c00000005221 ~]$ nc 172.16.80.70 1337

Hey Debu,did you know we can chat on the console like this?
@Rick, yeah! It's so cool man..


Ctrl+d


Network Scan:


range="172.16.80."; port=80; for host in $(seq 1 255); do multi_task=$(result=$(nc -zv $range$host $port 2>&1 | grep succeeded); if [ -n "$result" ]; then echo $range$host":"$port >> "/tmp/pscan"; fi;) & done



Cheers!

DK

Sunday, September 12, 2010

How To Copy Windows CMD Output!!



Pipe the command to windows clipboard with the command ( | clip) and then paste(ctrl+v) it anywhere you want. yes! This example is something that your network admin asks the most. They need prove...always!!

Anyway - who says, tricks in *nix only makes the geeks rock!! After all Bill is still my trusted Gateway to reach Torvald !!! :-)

RCA - Root Cause Analysis

An important step in finding the root causes of issues or occurrences that happen within a system or organization is root cause analysis (RC...