What is the role of IIS

IS provides a redesigned WWW architecture that can help you achieve better performance, reliability, scalability, and security for our Web sites. IIS can support following Protocol HTTP/HTTPS, FTP, FTPS, SMTP Etc. We need to host the site on IIS, when request comes from client it first hits the IIS Server, then the server passed it to ASP.NET worker process to execute. Then the response also passes to client via IIS itself. 
Note only Hosting of Site we can create our FTP Server, SMTP Server using IIS itself. 
There are different version of IIS available like 5.1, 6.0, 7.0 etc

Windows Server 2008 - Windows Vista - Home Premium/ Ultimate - IIS 7.0 
Windows Server 2003 - IIS 6.0 
Windows XP Professional - IIS 5.1 
Now based on your working experience you can say that you have worked on IIS 5.1 and 6.0 or only IIS 7. Etc. 

material

• dns records
  A (address) Maps a host name to an IP address. When a computer has multiple adapter cards or IP addresses, or both, it should have multiple address records.
• CNAME (canonical name) Sets an alias for a host name. For example, using this record, zeta.microsoft.com can have an alias as www.microsoft.com.
• MX (mail exchange) Specifies a mail exchange server for the domain, which allows mail to be delivered to the correct mail servers in the domain.
• NS (name server) Specifies a name server for the domain, which allows DNS lookups within various zones. Each primary and secondary name server should be declared through this record.
• PTR (pointer) Creates a pointer that maps an IP address to a host name for reverse lookups.
• SOA (start of authority) Declares the host that's the most authoritative for the zone and, as such, is the best source of DNS information for the zone. Each zone file must have an SOA record (which is created automatically when you add a zone).
  
  
  RODC
  A read-only domain controller (RODC) is a new type of domain controller in the Windows Server® 2008 operating system. With an RODC, organizations can easily deploy a domain controller in locations where physical security cannot be guaranteed. An RODC hosts read-only partitions of the Active Directory® Domain Services (AD DS) database.
  Before the release of Windows Server 2008, if users had to authenticate with a domain controller over a wide area network (WAN), there was no real alternative. In many cases, this was not an efficient solution. Branch offices often cannot provide the adequate physical security that is required for a writable domain controller. Furthermore, branch offices often have poor network bandwidth when they are connected to a hub site. This can increase the amount of time that is required to log on. It can also hamper access to network resources.
  Beginning with Windows Server 2008, an organization can deploy an RODC to address these problems. As a result, users in this situation can receive the following benefits:
  • Improved security
  • Faster logon times
  • More efficient access to resources on the network
  Inadequate physical security is the most common reason to consider deploying an RODC. An RODC provides a way to deploy a domain controller more securely in locations that require fast and reliable authentication services but cannot ensure physical security for a writable domain controller.

  However, your organization may also choose to deploy an RODC for special administrative requirements. For example, a line-of-business (LOB) application may run successfully only if it is installed on a domain controller. Or, the domain controller might be the only server in the branch office, and it may have to host server applications.

  In such cases, the LOB application owner must often log on to the domain controller interactively or use Terminal Services to configure and manage the application. This situation creates a security risk that may be unacceptable on a writable domain controller.

  An RODC provides a more secure mechanism for deploying a domain controller in this scenario. You can grant a nonadministrative domain user the right to log on to an RODC while minimizing the security risk to the Active Directory forest.

  You might also deploy an RODC in other scenarios where local storage of all domain user passwords is a primary threat, for example, in an extranet or application-facing role.
  
  
  new functionality
  
  

  • Read-only AD DS database
    
  • Unidirectional replication
    
  • Credential caching
    
  • Administrator role separation
    
  • Read-only Domain Name System (DNS)

study material

how to direct client authentication to another dc????

renaming dc

netdom computername old dcname /add:new dc

http://www.msexchange.org/tutorials/domain-rename.html

http://technet.microsoft.com/en-us/windowsserver/bb405948.aspx#top

What is Round Robin and Netmask Ordering

DNS Round Robin is a mechanism for choosing an IP address from the list returned by a DNS server so that all clients won't get the same IP address every time. Netmask ordering is a mechanism for further optimizing which IP address is used by attempting to determine the closest result.

842197 Description of the netmask ordering feature and the round robin feature in Windows Server 2003 DNS http://support.microsoft.com/default.aspx?scid=kb;EN-US;842197

The netmask ordering feature is used to return addresses for type A DNS queries to prioritize local resources to the client. For example, if the following conditions are true, the results of a query for a name are returned to the client based on Internet protocol (IP) address proximity:

You have eight type A records for the same DNS name.

Each of your eight type A records has a separate address.

The round robin feature is used to randomize the results of a similar type of query to provide basic load-balancing functionality. In the earlier example, eight type A records with the same name and different IP addresses cause a different answer to be prioritized to the top with each query. Because a new IP address is prioritized to the top with each query, clients are not repeatedly routed to the same server.

The key points here are that DNS Round Robin only provides a simple load-balancing system by alternating the IP at the top of the list the DNS server returns and that Netmask Ordering will return a list with the "closest" IP at the top of the list the DNS server returns. Both are server side mechanisms commonly used to provide simple load balancing functionality.

The registry size limit is exceeded. Additionally, the following event message is logged in the System log:

Event Type: Error

Event Source: Srv

Event Category: None

Event ID: 2020

Date: Date

Time: Time

User: N/A

Computer: Server Name

Description: The server was unable to allocate from the system paged pool because the pool was empty.

Nonpaged Pool

The kernel and device drivers use nonpaged pool to store data that might be accessed when the system can’t handle page faults. The kernel enters such a state when it executes interrupt service routines (ISRs) and deferred procedure calls (DPCs), which are functions related to hardware interrupts. Page faults are also illegal when the kernel or a device driver acquires a spin lock, which, because they are the only type of lock that can be used within ISRs and DPCs, must be used to protect data structures that are accessed from within ISRs or DPCs and either other ISRs or DPCs or code executing on kernel threads. Failure by a driver to honor these rules results in the most common crash code, IRQL_NOT_LESS_OR_EQUAL.

Nonpaged pool is therefore always kept present in physical memory and nonpaged pool virtual memory is assigned physical memory. Common system data structures stored in nonpaged pool include the kernel and objects that represent processes and threads, synchronization objects like mutexes, semaphores and events, references to files, which are represented as file objects, and I/O request packets (IRPs), which represent I/O operations.

http://www.simple-talk.com/sysadmin/general/troubleshooting-nonpaged-and-paged-pool-errors-in-windows/

Paged Pool

Paged pool, on the other hand, gets its name from the fact that Windows can write the data it stores to the paging file, allowing the physical memory it occupies to be repurposed. Just as for user-mode virtual memory, when a driver or the system references paged pool memory that’s in the paging file, an operation called a page fault occurs, and the memory manager reads the data back into physical memory. The largest consumer of paged pool, at least on Windows Vista and later, is typically the Registry, since references to registry keys and other registry data structures are stored in paged pool. The data structures that represent memory mapped files, called sections internally, are also stored in paged pool.
Paged pool memory is a region in virtual memory which can be paged in and paged out of the system. Device driver which do not need to access the memory from DPC/Dispatch level or above can use paged pool. it is accessible from any process context.

Device drivers use the ExAllocatePoolWithTag API to allocate nonpaged and paged pool, specifying the type of pool desired as one of the parameters. Another parameter is a 4-byte Tag, which drivers are supposed to use to uniquely identify the memory they allocate, and that can be a useful key for tracking down drivers that leak pool, as I’ll show later.

Event ID: 2020
Source: Srv
Description: The server was unable to allocate from the system paged pool because the pool was empty.

-or-

Event ID: 2019
Source: Srv
Description: The server was unable to allocate from the system nonpaged pool because the pool was empty.

Windbg is a tool for debugging windows memory dump…………..