DNS record explanations

DNS records, (or Resource Records) are stored in the zone file for a domain name and are used for translating domain names to IP addresses. They also contain other data, including Domain Name System, (DNS) server, Mail server and Alias information.

Modifications to your DNS Record may take approximately 12 - 24 hours to be acknowledged by the DNS for your account.

Record Explanations:

A Record
The A Record, (Address Record or IP Address), for a domain name is used to specify the physical address on the Internet that a user must connect to in order to use the information associated with that domain name, such as web site files or other types of data. For instance, if a web site for the domain name exampledomainname.com exists at the address 123.123.123.123, the IP Address for that domain name will be set to 123.123.123.123 in the zone file on that domain name's authoritative DNS.

AAAA Record
The AAAA Record, (Address Record or IP Address), is very similar to an A record in that it is used to associate a domain name with the IP address of the corresponding service (i.e. a website such as www.register.com ). However, these records are used to specify an IPv6 (Internet Protocol version 6) address record rather than an IPv4 (Internet Protocol version 4) address record as the A Record does. AAAA records are 128 bits in length and are typically represented in hexadecimal notation as such: 2001:06b0:1:00ea:0202:a5ff:fecd:13a6.

CNAME Record
A CNAME (Canonical Name or Domain Alias) section of a zone file, is an extension to a domain name that allows the creation of derivatives of the domain name which can be pointed to the same (or any other) domain name on the Internet. An example of a Domain Alias is www.register.com points to Register.com, where "www" functions as the Domain Alias and accesses the same web site as Register.com.

MX Record
The MX Record, (Mail Exchange Record), is the section of a domain name's zone file whose entries specify the mail server(s) on the Internet responsible for email distribution for a specific domain name. Any mail sent to an email address at a domain name must be routed on the Internet through the mail servers specified in the MX Record for that domain name, in order to reach the recipient.

TXT Record
TXT records are used to describe an entry in a zone file. The description can be anything that fits into 255 characters or less. TXT records are often used to support Sender Policy Framework, (SPF), an authentication system for email.

SRV Record
SRV (service) records allow flexibility and stability to services making use of them. Like a "general use" MX record, the SRV records relate to a particular service of the domain, like FTP or SIP, rather than a specific machine the way A or C-name records do.

Several programs are starting to make use of SRV records for such purposes as FTP, telnet and security applications, and they are commonly used for newer applications such as voice over IP.

A cluster of computers can be specified for a given service, with differing priority and "weighting" assigned, so a system or server administrator can specify both the order in which the machines are queried and the proportion of requests each server would handle. This allows a slower machine to take a smaller amount of the traffic, creating a greater efficiency of the service, and in other words, balancing the traffic load.

PTR Record
The PTR Record (Pointer or Reverse Record) can be thought of as the opposite of an A Record. This is what allows a reverse DNS lookup, (where an IP Address is used to map, or determine what your host/domain name is).

Not every IP address has a corresponding PTR record, however they are sometimes required for diagnostic or security purposes. PTR records are added to reverse zones.

Windows 2003 Server 2 NIC/Network Cards Multi-homed connection

Make sure you either have or can install Routing & Remote Access (should be in Administrative Tools)
If you need to install it, just do so with basic NAT/Firewall checked (one of the options required to install RRAS - Routing and Remote Access Service), but we're not going to use NAT.

Remove your gateways from your adapters (by going to your NIC->TCP/IP Properties->Advanced->Gateways->Remove (hopefully you can get my drift))

In the RRAS snap-in, right click on Static Routes and add a new route.
(I'm going to assume that your LAN connections are named "Network Card 1" and "Network Card 2" respectively for ease of typing)
Set this up:
Interface: Network Card 1
Destination: 0.0.0.0
Network mask: 255.255.255.255
Gateway: 192.168.0.1
Metric: 1

Click ok, and right-click "Static routes" and add another new route:
Set this up:
Interface: Network Card 2
Destination: 0.0.0.0
Network mask: 255.255.255.255
Gateway: 192.168.0.2
Metric: 1

Click "OK" and then right-click on "static routes" and click "show ip table"
make a note/screenshot of it as it is now

Go back to your network adapter
properties, go to the "Network Card 1" properties
Go to TCP/IP Properties->Advanced->Gateways->"Add"
Gateway: 192.168.0.1
Automatic Metric: UNCHECKED
Metric: 20
Close out of that

go to the "Network Card 2" properties
Go to TCP/IP Properties->Advanced->Gateways->"Add"
Gateway: 192.168.0.2
Automatic Metric: UNCHECKED
Metric: 20

Now get a new list of the routes in your IP routing table by going into the RRAS snap-in, right click on "static routes" and click "show ip routing table"
You should have at the top, something like this (the first 4 lines are the critical ones, if these aren't right, re-try the order in which you setup the static routes & add the gateways)

Destination Network Mask Gateway Interface Metric Protocol
0.0.0.0 255.255.255.255 192.168.0.1 Network Card 1 1 Static (non...)
0.0.0.0 255.255.255.255 192.168.0.2 Network Card 2 1 Static (non...)
0.0.0.0 0.0.0.0 192.168.0.1 Network Card 1 20 Network Mgmt
0.0.0.0 0.0.0.0 192.168.0.2 Network Card 2 20 Network Mgmt

Be sure to make your destination NAT on your routers MATCH from router to IP resepectively, or the whole thing won't work, ie:
router: 192.168.0.1 needs to forward traffic to 192.168.0.5
router: 192.168.0.2 needs to forward traffic to 192.168.0.4

Essentially what you're doing is bonding a gateway to a NIC. This may work for you, it has definately worked for me when I needed to setup a web server that would respond on 2 different public IP's.

Recover from a Corrupted Registry in Windows XP

When Will This Recovery Work?
You'll want to use the steps on this page to recover from a corrupted registry when you have already tried other options such as System Restore and you receive a message similar to one of the following when you try to boot your computer with Windows XP

.

• Windows XP could not start because the following file is missing or corrupt: \WINDOWS\SYSTEM32\CONFIG\SYSTEM
  
  
• Windows XP could not start because the following file is missing or corrupt: \WINDOWS\SYSTEM32\CONFIG\SOFTWARE
  
  
• Stop: c0000218 {Registry File Failure} The registry cannot load the hive (file): \SystemRoot\System32\Config\SOFTWARE or its log or alternate
  
  
• System error: Lsass.exe
  
When trying to update a password the return status indicates that the value provided as the current password is not correct.

Be careful using this procedure in other circumstances or with an OEM version of Windows XP since OEM installations create passwords and user accounts that did not exist previously and may cause you not to be able to log into the Recovery Console to restore files.

Booting into the Recovery Console

You'll need to use the Windows XP Recovery Console to fix a corrupted registry, this will either require you to boot from a Windows XP Installation CD or boot directly to the Recovery Console if its installed. Follow these steps to boot into the Recovery Console from a Windows XP Installation CD.

1) Place your Windows XP in the CD-ROM Drive
2) Restart your computer and make sure your BIOS is set to boot from CD
3) When you see the following command press the space bar.

"press any key to boot from cd..."

4) Wait until you see the "Welcome to Setup" screen, and press R to start the Recovery Console
5) Choose which Windows installation you wish to load (this is usually #1 unless you have a multi-boot system)
6) Type the administrator password and Press Enter
7) You should now be at the C:\Windows> prompt

Copy Repair Files Using the Recovery Console

This procedure assumes Windows is installed on Drive C, if you have installed Windows on another drive, please substitute the appropriate drive letter in the procedure below.

At the Recovery Console command prompt, type the following lines, pressing ENTER after you type each line:

md tmp
copy c:\windows\system32\config\system c:\windows\tmp\system.bak
copy c:\windows\system32\config\software c:\windows\tmp\software.bak
copy c:\windows\system32\config\sam c:\windows\tmp\sam.bak
copy c:\windows\system32\config\security c:\windows\tmp\security.bak
copy c:\windows\system32\config\default c:\windows\tmp\default.bak

delete c:\windows\system32\config\system
delete c:\windows\system32\config\software
delete c:\windows\system32\config\sam
delete c:\windows\system32\config\security
delete c:\windows\system32\config\default

copy c:\windows\repair\system c:\windows\system32\config\system
copy c:\windows\repair\software c:\windows\system32\config\software
copy c:\windows\repair\sam c:\windows\system32\config\sam
copy c:\windows\repair\security c:\windows\system32\config\security
copy c:\windows\repair\default c:\windows\system32\config\default

Type exit to quit Recovery Console. Your computer will restart, press F8 as it starts and choose Safe Mode.


Restart in Safe Mode and Find a Recent Snapshot Backup

Restart your computer in Safe Mode by pressing F8 during the initial bootup and choosing Safe Mode. Once in Safe Mode, you need to make sure the files and folders are visible so you can access them. Follow these instructions to accomplish this.

1. Open My Computer
2. Click on the Tools menu, then click Folder Options.
3. Click the View tab.
4. Under Hidden files and folders, click to select Show hidden files and folders, and then click to clear the Hide protected operating system files (Recommended) check box.
5. Click Yes when the dialog box that confirms that you want to display these files appears.

In My Computer, Double-click the drive where you installed Windows XP (usually Drive C) to display a list of the folders. then double-click on the "System Volume Information" folder. This folder contains the system restore points stored on your computer. The folders will look similar to

_restore{EE42BEB8-700A-495F-8004-53D26C2E12C5}

You might receive an access denied error message similar to the following when trying to access the System Volume Information folder.

C:\System Volume Information is not accessible. Access is denied.

This is generally caused because the user you are logged in under does not have permissions set on the folder. To fix this, follow the instructions in the Microsoft Knowledge Base article 309531 to gain access and continue. Each version of Windows XP is different on how to change these permissions.

Once you have access to the snapshots, use the instructions below to copy one of the latest snapshots to the Windows\TMP directory so you have access to it.

1) In the System Volume Information Folder, click on View, and then click Details to display the date of each snapshot folder.
2) Double-click on a folder that was not created at the current time but rather before the problem started.
3) Double-click on the Snapshot subfolder
4) Using your normal windows copy and paste techniques, highlight the following files and copy them into the C:\Windows\TMP folder

• _REGISTRY_USER_.DEFAULT
• _REGISTRY_MACHINE_SECURITY
• _REGISTRY_MACHINE_SOFTWARE
• _REGISTRY_MACHINE_SYSTEM
• _REGISTRY_MACHINE_SAM
  

5) Rename the files that you just copied into the C:\Windows\TMP folder by right-clicking on each filename and choosing Rename, then typing the new name. Repeat this for each file in the list below.

• Rename _REGISTRY_USER_.DEFAULT to DEFAULT
• Rename _REGISTRY_MACHINE_SECURITY to SECURITY
• Rename _REGISTRY_MACHINE_SOFTWARE to SOFTWARE
• Rename _REGISTRY_MACHINE_SYSTEM to SYSTEM
• Rename _REGISTRY_MACHINE_SAM to SAM
  

6) Once you have renamed the files, restart your computer again with the Recovery Console (refer to the instructions above to do this)


Replace the Repair Files with a Current Backup of the Registry

After rebooting the computer and starting the Recovery Console again, type the following commands at the prompt to replace the files with a current backup. You'll need to press Enter after each command.

del c:\windows\system32\config\sam
del c:\windows\system32\config\security
del c:\windows\system32\config\software
del c:\windows\system32\config\default
del c:\windows\system32\config\system

copy c:\windows\tmp\software c:\windows\system32\config\software
copy c:\windows\tmp\system c:\windows\system32\config\system
copy c:\windows\tmp\sam c:\windows\system32\config\sam
copy c:\windows\tmp\security c:\windows\system32\config\security
copy c:\windows\tmp\default c:\windows\system32\config\default

After the files have been replaced, type EXIT at the command prompt to restart Windows in normal mode.

Use System Restore to Return to a Good Backup Point

Because there is more to a System Restore than just the registry files, follow these steps to restore your computer to a good backup point.

1. Click Start, and then click All Programs.
2. Click Accessories, and then click System Tools.
3. Click System Restore, and then click Restore to a previous Restore Point and finish the restore.