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Google Doodles: World Cup 2014 #27

Google Doodles: World Cup 2014 #27

Hi ,

Today Google posted new doodle !

Its so true XD

World Cup 2014 #27 doodles by Google
World Cup 2014 #27

 

 

Official Google doodles website

Activate mail service on domain button is greyed out

0

Symptoms

Mail service is disabled for subscription in * *> Mail > Mail Settings and it is not possible to enable it through control panel, because“Activate mail service on domain” button is greyed out, but subscription is active.

Resolution

  1. Create dump of Plesk database:

Plesk for Windows 
C:Program FilesParallelsPleskMySQLbin>mysqldump -uadmin -pPASSWORD -P8306 psa >psa.dump 
Plesk for Linux 
mysqldump -uadmin -pcat /etc/psa/.psa.shadow psa >psa.dump

  1. Login to Plesk database:

Plesk for Windows C:Program FilesParallelsPleskMySQLbin>mysql -uadmin -pPASSWORD -P8306 psa

Plesk for Linux 
mysql -uadmin -pcat /etc/psa/.psa.shadow psa

  1. Find domain with disabled mail service:

    mysql> select * from DomainServices where type='mail' and dom_id=(select id from domains where name='domain.tld'); +-----+--------+------+--------+---------------+----------------+ | id | dom_id | type | status | parameters_id | ipCollectionId | +-----+--------+------+--------+---------------+----------------+ | 167 | 61 | mail | 2 | 229 | 167 | +-----+--------+------+--------+---------------+----------------+ 1 row in set (0.00 sec)

where ‘domain.com’ is a primary subscription’s domain.

mysql> update DomainServices set status=0 where type='mail' and id=167; Query OK, 1 row affected (0.00 sec)

Cause

Such kind of misconfiguration could be the result of manually changed parameters in database.

Switching off and on mail service for a domain in Plesk

0

Switching off and on mail service for a domain in Plesk

 

Hello ,

Switch off and on mail service for domain in plesk systems .

Will disable mail service for the domain ‘thedomain.com’. It’s necessary if the domain has externally hosted email.

Plesk Windows:

 

Please Linux:

Off

On

Installing MCrypt PHP5 on Ubuntu 12.04

Installing MCrypt PHP5 on Ubuntu 12.04

Hello ,

MCrypt is a replacement for the popular Unix crypt command.

Mcrypt provides the same functionality but uses several modern algorithms such as AES. Libmcrypt, Mcrypt’s companion, is a library of code which contains the actual encryption functions and provides an easy method for use.

It implements numerous cryptographic algorithms, mostly block ciphers and stream ciphers, some of which falls under export restrictions in the United States. Algorithms include DES, Blowfish, ARCFOUR, Enigma, GOST, LOKI97, RC2, Serpent, Threeway, Twofish, WAKE, and XTEA.

To install MCrypt  for PHP5 on Ubuntu 12.04 Linux system ;

apt-get install php5-mcrypt

or with root privileges

sudo apt-get install php5-mcrypt

After installing MCrypt you need to restart Apache ;

/etc/init.d/apache2 restart

or with root privileges

sudo /etc/init.d/apache2 restart

 

For more info about mcrypt, visit:

Official site

http://mcrypt.hellug.gr

PHP usage of mCrypt

http://www.php.net/manual/en/book.mcrypt.php

 

 

Microsoft Virtual Academy (MVA)

Microsoft Virtual Academy (MVA)

The Microsoft Virtual Academy (MVA) is a free online school with courses that cover Microsoft-related topics and specific Microsoft products.

The MVA offers a mix of on-demand courses and live events; each course contains a video and PDF download of the video transcript. A self-assessment component is available at the end of each module. Students are awarded points and can move to different levels of recognition based on the progress they make. Points are earned by watching videos, downloading video transcripts and self-assessment quizzes; the more points a member earns, the more opportunities she is given to participate in other MVA offerings. A leaderboard tracks the most active members. Although MVA offers free training for Microsoft certifications, members cannot earn certification directly through the Academy.

Topics offered through the MVA include business intelligence (BI), server infrastructure, desktop management and device security, licensing, programming and cloud computing. The coursework is designed to help lifelong learners work more effectively with Microsoft Lync, SharePoint, System Center, Office 365, SQL Server, Visual Studio, Windows Azure, Windows Phone and Windows Intune.

MVA coursework is hosted on Windows Azure and video access requires Microsoft Silverlight.

Sign-in / register now for FREE to Microsoft Virtual Academy (MVA) just by using your Windows Live-ID 🙂

Hyper V on Windows 8 and the GeForce 337.50 Beta Driver

Hello everyone 🙂

Lately i have upgrade my GeForce 660TI to 337.50 Beta Driver .

On my PC i have many programs , and one of the programs that i run is Hyper-V on Windows 8 SP1.

After removing Oracle VM VirtualBox, i get a screen full of surprises…

In event viewer you can see this error : Event ID: 1 Source: ApplicationExperienceInfrastructure

The application (<application name>, from vendor <vendor name>) has the following problem: <program name> is incompatible with this version of Windows. For more information, contact <vendor name>.

In my case :

В приложении (Oracle VM VirtualBox, поставщик Oracle Corporation) возникла следующая проблема: Для правильной работы необходимо переустановить Oracle VM VirtualBox после обновления Windows.

You may see more information regarding that error on EventID.

 

After reboot , you get more errors in event viewer : Event ID: 1000 Source: Application Error

Faulting application <application name>, version <version number>, faulting module <module name>, version <version number>, fault address <hex address>.

or in my case :

Имя сбойного приложения: nvcplui.exe, версия: 7.7.740.0, метка времени: 0x53336fbe
Имя сбойного модуля: nvcplui.exe, версия: 7.7.740.0, метка времени: 0x53336fbe
Код исключения: 0x40000015
Смещение ошибки: 0x00000000001c8615
Идентификатор сбойного процесса: 0x92c
Время запуска сбойного приложения: 0x01cf64b7d6770d2c
Путь сбойного приложения: C:Program FilesNVIDIA CorporationControl Panel Clientnvcplui.exe
Путь сбойного модуля: C:Program FilesNVIDIA CorporationControl Panel Clientnvcplui.exe
Идентификатор отчета: 1463f798-d0ab-11e3-be80-94de80002f33
Полное имя сбойного пакета:
Код приложения, связанного со сбойным пакетом:

You may see more information regarding that error on EventID.

 

Solution to fix this ,

Try to remove all the GeForce Beta Driver and install the WHQL only .

I recommend you to remove the adapter in device manager and re install all again with WHQL Driver .

 

Good luck !

🙂

Secure your Plesk panel with an SSL certificate and Secure the Panel

2

SSL installation on plesk server administrator

 

Hi all ,

Today i will write about installing SSL certificate on the main Plesk Panel .

For the Test environment i will use :

1) Windows 2008 R2 64 bit

2) Parallels Plesk Panel 11.5.30 Update #43

Lets start the installation 🙂

download

P.s. I used official software from Microsoft and Parallels Plesk for testing purpose only hosted by InterSpace.

VirtualBox -virtualization product

Hello members .

I have found nice product that called VirtualBox.
I have installed Win 7 RC and Virtual machine provided by Microsoft not working (P.s. no VT in my laptop  )…
I needed a new “help”
I found a new Open Source Software… Thats works in Win 7 and works graet … not so good like Virtual machine but i got a no chance  .

————
Discription:
VirtualBox is a powerful x86 virtualization product for enterprise as well as home use. Not only is VirtualBox an extremely feature rich, high performance product for enterprise customers, it is also the only professional solution that is freely available as Open Source Software under the terms of the GNU General Public License (GPL). See “About VirtualBox” for an introduction.

Presently, VirtualBox runs on Windows, Linux, Macintosh and OpenSolaris hosts and supports a large number of guest operating systems including but not limited to Windows (NT 4.0, 2000, XP, Server 2003, Vista, Windows 7), DOS/Windows 3.x, Linux (2.4 and 2.6), Solaris and OpenSolaris, and OpenBSD.

VirtualBox is being actively developed with frequent releases and has an ever growing list of features, supported guest operating systems and platforms it runs on. VirtualBox is a community effort backed by a dedicated company: everyone is encouraged to contribute while Sun ensures the product always meets professional quality criteria.
————

That software is coming free and it comes with monthly (+ / – ) ubdates and hot fixes ..
I readed more on that product and descovered that after instaling host OS you can play games in it by installing them … (for exmaple Call of Duty ) ..
This product is provided by В© 2009 Sun Microsystems, Inc.
..

Who use Win 7 or ather platform that not support Virtualization or Microsoft Virtual machine is not working.. that softwere will let you to do it and its nice when you have 3 party softwere

P.S. That softwere is NOT a replacement of Microsoft Virtual Machine. Microsoft Virtual Machine (Products)is better and etc .
That softwere is just a replacement and for testing … not more ..

Good luck .

Using Winroute Lite

Using Winroute Lite

Hello everyone ,

Currently i am using Winroute Lite 4.2.5 software for NAT purpose in window XP to route my software VPN clients.

WinRoute Lite offers a fast and easy solution for sharing a single Internet connection for your entire network. With firewall security and newly added network functionality such as port mapping and support for multimedia, online gaming and IP telephony, WinRoute Lite proves to be an ideal solution for home and small office networks. Now compatible with Windows® 9x, ME, 2000 and NT4.0.

This version is not being support to windows 7 so any guys can suggest me another software like winroute lite 4.2.5 for windows 7 or supported windows 7 winroute version.

Ok , as i think the winroute is know change his name and have no updates and etc …

Did you tried to check it with compatibility mode in windows 7 to compatibility to win XP or Win 2000 ?

Yes , that version is not supporting and any other product is not , the company change the name and upgraded the need and products .

I you wona to have almost the same product its name is Kerio Control .

Its supports win 7 and etc .

You can read about it her :

 

P.S. I think you need to upgrade to the new software , because you are now outdated and the new product is very nice with many tweaks .

P.S. Are you looking for some open source software ?

P.S. You can try the beta Kerio Control free just check in the web site product and read about it if you wona this software

Good luck .

Outlook Disconnecting Frequently

Outlook Disconnecting Frequently

Hello ,

I will describe one of the problems that i got couple of years ago ,

On a server that is running Microsoft Exchange Server 2007 and windows server 2003 SP2, an event that
resembles the following event is logged in the Application log:

Event Type: Error
Event Source: MSExchangeIS
Event Category: General
Event ID: 9646
Description:
Closing Mapi session “/o=Organization/ou=Administrative
Group/cn=Recipients/cn=Recipient” because it exceeded the maximum of 32
objects of type “session”.

All MAPI client Getting Disconnting frequently/ Offline/ not connecting to Exchange server .

This problem may occur if a MAPI client opens more than the default value of the server objects.

This error is common and may have many fixes to it .

There is three common ways to fix it :

1) Windows 2003 SP2 introduced a feature called scalable networking. Disabling it immediately fixed the problem of Outlook clients using too many sessions. To disable without rebooting enter the following at a command prompt:

netsh int ip set chimney diabled

To permanently disable (reboot required), set the following registry value to 0:
HKEY_LOCAL_MACHINESYSTEMCurrentControlSetServicesTcpipParametersEnableTCPChimney.

2) Look at Exchange System Manager/Servers/<server>/<storage group>/<mailbox store>/logons. Visually find the user name (if this name is not known from log, as it was in my case) which exceeded 32 sessions. It is a pity that there is no way of using ESM to close these sessions. To do this, find the user’s IP address, open tcpview.exe (from Sysinternals) and close all connections to store.exe generated by that IP.
Errors with exceeded “sessions” were generated after the user tried to send a large e-mail and were caused by broken network cable on user’s workstation.

3) Use that KB that posted by MS:

P.S.
That link may help you too … (its about exchange 2003 but its the same +/- :))) ) 🙂

 

Find out who did (Delete records)what via an ip address or a network address? (no audit)

Find out who did (Delete records)what via an ip address or a network address? (no audit)

Hello .

Before the damagedisasterdeletion you need to turn on the audit logs to all as especially to who use very important data .

If the records (Data) missing its a low (very low) chance to track and see who did it and when .

You can check Event Viewer on the server maybe some tracks are left but its low chance .

The question is why didnt you put audit logs on extremely important files and records and why you didnt put some permissions on thous datarecordsfolder .

If you do some backups you can see and restore the data …. but if you do backup on thous records .

——————-
Some solutions :

1) If you have an office with some sort off 25 PCs … you may check Event Viewer in all of thous PCs (you may find some sort of tracks) … or the PCs that have access to thous foldersrecordsdata.
2) Check Event Viewer on the server (you may find some sort of tracks)
3) You can use to some recovery 3th party programs … … … problematically but you can check . …

——————-
Advice :

1) Always audit important data , users that using them and any one that opensdeletes etc .. . ( even in the users PCs do it ) 🙂

2) Always Backup important data !!!

3) Give permissions correctly to users that use important files .

4) Do an real secure form org. with firewall that stops attacksGPO configured to securitylock some files etc etc etc .

5) Configure GPO correctly )

6) Configure database security correctly . ..

Sit couple of days and do it … if that was the first one ( attack ) it would be second .. . be in low profile and you would track the thief .

Good luck .

How to forward incoming and outgoing mails in Outlook

How to forward incoming and outgoing mails in Outlook

 

Hello ,

The only thing that could help is to create a rule in Microsoft Outlook program.

The thing is that the rule you need to do that localy on a pc .

If you are using Exchange server the thing is way better to do to many users , but if you have no so many users its only a meter of time to do that or the meter of user that can disable it .

The creation of the rules is the same about in office 200320072010 .

P.S. You can see that in MS site :
hcxxcxcp://office.microsoft.com/en-gb/outlook-help/automatically-forward-messages-to-another-e-mail-account-HA001150201.aspx

————————-

Same that the 1 image you are getting in to the :
-Rules and Alerts.
-New Rule.
-Start from a blank rule.
-Apply rule on massage i send

The way is the same )))) You configure +/- same ) ) )

How to block websites using ADS Groups/OU

How to block websites using ADS Groups/OU ?

Ok .
Question, do you use firewall like ISA etc ..
————————–
Block some web sites via GPO can be done … but the nice way is throw firewall )
You can do it by HOST file or GPO too or DNS) )
————————–
P.S.
For the blocking of file uploads especially through like bit torrents or via IM you have your work cut out. Traditional firewalls have a hard time blocking that stuff because the ports for those types of programs tunnel through ports that are already open on the firewall. I would like a some type of Intrusion Prevention System or Layer 7 firewall. Again ISA 2006 is a good canidate.
————————-
1)One thing you can do to block certain sites without ISA server is to deploy a custom hosts file using a startup script.
For the sites you want to block you would add a static entry into a hosts file that pointed to an invalid ip like 0.0.0.0
your batch file would look kind of like this:

————————-
or
——–

2) Or you can do it with DNS, create A records for those sites pointing to 127.0.0.1
————————

P.S. Theres a way to block IP in GPO so the IP of the site will be blocked )))

3)
-Click on Start and select “Run…” again. Type “gpedit.msc” without the quotes and press “Enter”. This will launch your Group Policy Editor.
-Navigate to the following location in the left panee under “Group Policy”: “Navigate to Computer configuration” > “Windows Settings” > “Security Settings” > “IP security Policies”.
-Right-click anywhere in the right pane and click on “Manage IP Filter Lists…” Hit the “Add” button to name the group policy.
-Typee a name and hit “Add”. Click on “Next” and select “My IP address”. Enter the IP address of the website you want to block. Hit “OK”. Repeat these steps to block additional websites using Group Policy.

Good luck ,

How to tell if a site is secure ?

2

How to tell if a site is secure ?

Lets start with some basics things Like:

1)Encryption: What Is It?
What Is It?

Encryption is the process of scrambling a message so that only the intended audience has access to the information. As more people share confidential data and applications using the Internet, they have come to rely on commercially available Secure Sockets Layer (SSL) encryption.

When an SSL handshake occurs between a client and server, a level of encryption is determined by the Web server, the client browser, the client operating system, and the SSL Certificate. Low-level encryption, 40 or 56 bits, is acceptable for sites with low-value information. High-level encryption, at 128 bits, can calculate 288 times as many combinations as 40-bit encryption. That’s over a trillion times a trillion times stronger.
(Now its by default is 128/256 bit… especial 256 on the big sites (cost a lot ) and 128 on the regular sites)

2) Web pages beginning with “https” instead of “http” enable secure information transmission via the protocol for secure http. Securing networks and applications is essential to secure online transactions. “Https” is one measure of security to look for when sending or sharing confidential information such as credit card numbers, private data records, or business partner data. However, it may not be enough.

Certificate Authorities use different authentication methods and levels to verify information provided by organizations requesting SSL Certificates. The most basic SSL Certificate only verifies domain name control, a low-level of authentication that may be used by fraudsters to make their sites appear trusted.

————————————————————————————————————–

Lets Start… :

1) If you are visiting the website with a secure connection, you will be able to identify the website through the site’s certificate. A secure or encrypted website address will begin with HTTPS rather than HTTP (*), and you will see a lock icon in the Address bar(*). Secure connections use certificates to identify the website and to encrypt your connection so that it will be more difficult for a hacker to view. You can also click the lock icon in the Address bar to see more information about the website and the CA with that gave that cert. to the web site.
When you click the lock icon in the Address bar, you can see the security report. Depending on the type of certificate the website has, you can see the website address or the company address that the certificate was issued to (*).
Extended Validation (EV) certificates will turn the Address bar green, and will contain a confirmed name and address for the website owner(*).
Non-EV certificates will display the website address or the domain of the site. If the security report only shows the website’s address, be sure it is the address you wanted to visit. Phishing or fraudulent websites will often use similar website names to trick visitors into believing they are visiting trusted sites.

(*)hxxp://img708.imageshack.us/img708/4456/38362704.png
(*)hxxp://img801.imageshack.us/img801/9393/86726445.png
(*)hxxp://img844.imageshack.us/img844/5881/86618788.png
(*)hxxp://img195.imageshack.us/img195/8669/36813239.png

2) If you are asked for personal information, such as credit card numbers or bank information, only provide it if there is a good reason to do so. Also, make sure there is a secure entry form for recording information. Look for a message stating that the information will be encrypted and check for the lock icon in the Security Status bar in the Internet Explorer Address bar (do not enter confidential information if there is no lock icon on the Address bar!!!). You should be confident that the site is using your information properly and in a secure manner before providing any information inc. credit card number , cellphone , address and etc….

3) Do they have a phone number that you can call if you have a problem, or that you can use to place an order? Does the website list a street address? Is there a posted return policy with acceptable terms? If the site doesn’t provide a phone number or physical address, try contacting the company by e‑mail to ask for that information.
P.S. (One of the none needed info for advanced users … and its only (maybe,not always) for a big comp. like: eBay,Amazon and etc… )

4) Different colors in the Security status bar and the explanation to them:
When you visit a website that uses a secure connection, the color of the Security Status bar tells you whether the certificate is valid or not, and it displays the level of validation that was performed by the certifying organization.
The following table describes what the Security Status bar colors mean:
Red – The certificate is out of date, invalid, or has an error.
Yellow – The authenticity of the certificate or certification authority that issued it cannot be verified. This might indicate a problem with the certification authority’s website.
White -The certificate has normal validation. This means that communication between your browser and the website is encrypted. The certification authority makes no assertion about the business practices of the website.
Green – The certificate uses extended validation. This means that communication between your browser and website is encrypted and that the certification authority has confirmed the website is owned or operated by a business that is legally organized under the jurisdiction shown in the certificate and on the Security Status bar. The certification authority makes no assertion about the business practices of the website.

5) Spoofed and fake website creators are becoming very innovative in making their sites look like commercial sites. Even fake sites can be encrypted, so having a “secure” connection is not any guarantee that the website is legitimate. In addition to checking the address and looking for icons, try clicking in links and other images on the websites to see where you go on the website. Also look carefully at the address line and make sure it is spelled correctly.

6) If possible, use a new high-security Web browser that recognizes Web sites using Extended Validation (EV). If you’re using a high-security browser, ensure that the address bar turns green before entering personal information.
P.S. High-security Web browsers are new browsers that offer enhanced protection against viruses and attacks. They also are Extended Validation (EV)–enabled and display the verisign green bar when you visit an EV-secured Web page. These new browsers include Microsoft Internet Explorer 7, Firefox 3, Safari 5 ,Opera 10 (10.61) and etc… .

7) If a Web site has obvious and abundant typographical errors, avoid it. Why? Many phishing and spoofing sites originate in foreign countries and are written and programmed practically overnight.

8) Look closely at a sites URL in the address bar. A genuine Web site should include the company name immediately before the suffix. For instance, http : // www.sadikhov.com is a valid site. However, http : // www.sadikhov.1234.com may be a fraudulent Web site spoofing site.

9) Many SSL Certificate vendors (Verisign, GeoTrust, SSL.com, etc.) also provide a “site seal” to the owners of these web sites (*).
These site seals should not necessarily be trusted on their own, but should serve as a reminder to “investigate further”… .

(*)hxxp://img44.imageshack.us/img44/1990/49535288.jpg
hxxp://img580.imageshack.us/img580/5380/imagjes.jpg

10) A privacy policy. Most of us skip the privacy policies, but the shop that does not offer one should be the one to skip altogether.

11) Return policy.
Don’t get caught by surprise by ordering a super cool t-shirt which washes away on the first visit to the laundry. Before finalizing any order, check the return and refund policy.

12) And the last thing you can do is Google the sites name and behind their companies name enter the word complaints. Here you may find blogs and other valuable information that may not necessarily be on the web site. Read what you can about the website before placing your order.

—————————————————————————————————————

There is really no way to know ever if a site is 100% secure, but if you follow the few step’s provided here you will have a safer and more secure purchase.

The Basic things to be secure online are:
*Firewall ON
*AV is up to data
*OS is up to data
*Web Browser is up to data

TIPS :
A website might not be trustworthy if:

*ALL WEB PAGES ASKING YOU FOR SENSITIVE INFORMATION SHOULD BE SECURED USING SSL!!!
*THE LOCK ICON IS NOT JUST A PICTURE! 
*The site is referred to you through an e‑mail message from someone you don’t know.
*The site offers objectionable content, such as pornography or illegal materials.
*The site makes offers that seem too good to be true, indicating a possible scam or the sale of illegal or pirated products.
*You are lured to the site by a bait and switch scheme, in which the product or service is not what you were expecting.
*You are asked for a credit card as a verification of identity or for personal information that does not seem necessary.
*You are asked to provide a credit card number without proof that the transaction is secure.
*When in doubt, do not enter personal information.
*Only use companies that you are familiar with because anyone can set up a secure server.
*If you get a warning window that the certificate has expired when you enter a secure server, do not enter your personal information.

Hackers break SSL encryption used by millions of sites

Beware of BEAST decrypting secret PayPal cookies

The vulnerability resides in versions 1.0 and earlier of TLS, or transport layer security, the successor to the secure sockets layer technology that serves as the internet’s foundation of trust. Although versions 1.1 and 1.2 of TLS aren’t susceptible, they remain almost entirely unsupported in browsers and websites alike, making encrypted transactions on PayPal, GMail, and just about every other website vulnerable to eavesdropping by hackers who are able to control the connection between the end user and the website he’s visiting.

Good luck,
I hope i helped 
and be careful 
Credits to: Microsoft Security Team (that gave me some good words) and me ( kamtec1 ).

Password change in win7

Password change in win7

Hi .

Today i will explain Password change in win7 . For me that drastic change is quiet well  .

Yes in Windows 7 it changed drastically and i can explain it.

Since Windows NT 3.x, when your user password is 14 days from expiration, you receive a Password Change Notification when logging on requesting you to change your password.
This has been the default behavior up to now.
Windows 7 password change notification setting is set to 5 days by default.
If you wish to align your Windows 7 computers with others on the network, you can either modify the registry for the Windows 7 systems, or apply a local, or preferably, a group policy object if these Windows 7 systems are members of an Active Directory domain.
.

Option 1: Modify the Registry

1) Run Registry Editor (Regedt32.exe).
2) Navigate to HKLMSoftwareMicrosoftWindows NTCurrentVersionWinlogon
3) Add or modify the following entry: PasswordExpiryWarning: REG_DWORD:
4) Click OK and quit Registry Editor.

—-

Option 2: Apply a Local or Group Policy Object

1) Modify the existing local computer policy, modify an existing group policy object, or create a new group policy object and apply it to the target OU containing the target computers.
2) Navigate to the following path in the policy object
a)Computer ConfigurationWindows SettingsSecurity Settings Local Policies Security Options
b)Find the entry: Interactive logon: Prompt user to change password before expiration
3) Configure the attribute with the value that you require.

———————–

There is no other solution .

You can write on powershell script or .. but no more  .

This is the default behavior of windows 7 password notifications  , after thous 5 days the user will change the pass

Good luck,

Learning DNS for Enterprise

Learning DNS for Enterprise

I can tell you couple of things and a little facts about DNS :)))

There are two types of DNS queries, recursive and iterative.
When a DNS resolver issues a recursive query to a name server, the server attempts to resolve the name completely with full answers (or an error) by following the naming hierarchy all the way to the authoritative name server.

Upon receiving an iterative query, the name server can simply give a referral to another name server for the resolver to contact next.

A resolver sets the RD (recursion desired) bit in DNS query packet to indicate that it would like to have the query resolved recursively.

Not all servers support recursive queries from arbitrary rresolves… 🙁

– Instead of using your default name server, issue the query for www.test.edu to one of the
root DNS servers (e.g. a.root-servers.net). Does this server accept recursive query from
you? If not, perform iterative queries yourself using dig by following the chain of referrals to
obtain the www.test.edu address. What are the sequence of name servers that you have
queried? Which domain is each name server responsible for?

– Alice works at a search engine startup whose main competitor is Google. She would like to
crush her competitor in the “non-traditional” way by messing up with DNS servers…… Recalling
from her networking class that DNS servers cache A and NS records from DNS replies and
referrals, Alice realizes she can configure her own DNS server to return incorrect results for
arbitrary domains. If the resolver caches Alice’s malicious results, it will return bad results
to future DNS queries. Help Alice complete her master plan to hijack Google’s domain name
by writing down exactly what Alice’s name server returns upon a DNS query. What must a
robust DNS server implementation do to counter this attack?

– Use multiple recursive DNS servers located at different geographical regions1 as well as your
default name server to resolve www.google.com. Attach your dig output. What geographi-
cal regions do those IP addresses reside? How quickly do the corresponding A and NS records
expire? Why do A records expire so soon? Compare this setup using DNS with some alterna-
tive way of achieving the same goal.

———————-

Its very hard to explain to you . ..
Practically its a very dangerous thing is to touch the dns …. :))
May be someone ales can explain more specifically .

Good luck .