server 2008 infrastructure chp 5

Forwarders

Servers used to resolve names

For server core you use ___to install DNS role.

ocsetp

*DNS zones can perform two types of name resolution is in two directions* Forward Lookup Zones -

Forward Lookup Zones allow a DNS client to resolve an FQDN to an IP address. Forward Lookup Zones are the most commonly used DNS records on the internet and in private networks using DNS for name resolution. Communicating on the internet would be almost impossible without forward lookup zones.

roots provide _____ and are kept current on the computer via microsoft update.

IP address pointers to top level DNS servers

*The DNS Namesspace is organized into the following domains* Root Domain: (.)

Often represented by an implied decimal point, or dot, at the end of a domain name, the root domain is currently made up of 13 servers that provide referrals to all top-level domains. although all domain namespaces must start with a root domain, most software todat assumes this is the case, which you do not have to enter the last dot when entering URLs.

Master server

Provides updated DNS record information to secondary servers

Dynamic updates

Sometimes referred to as DDNS

Windows Server 2008

Supports dynamic updates with both standard and Active Directory Domain Services-integrated domains

When DNS is installed on a full version or windows server 2008, the DNS console is available through ___ and as a stand-alone in ___.

server manager ----- microsoft management console

After a Reverse lookup zone is created , pointer records(PTRs) are created to map the IP addresses to the host name of the node. These records can be created manually through the DNS console or from the command line or you can have the record created automatically when a forward lookup record, or an A record is created. Unlike forward lookup zones, reverse lookup zones are not required for active directory functionality or even name resolution in workgroup environments. You need reverse lookup zones in cases where application or nodes require a host name for known IP addresses.

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How do Forward Lookup Zones work?

First create a forward lookup zone to hold the records. Next create the records needed for resolution. Consider the example of the quizlet.net to allow DNS clients to resolve resources for quizlet.net, you need to create zone and records for the domain.

Mail exchanger (MX) record

Specifies the server that is responsible for handling e-mail

*DNS Resource Records*

The DNS database uses DNS resource records to store information about hosts, host names, and other information that DNS provides to DNS clients. Besides A records, many other resource records are used on networks for providing information to its clients.

Within the ___ domain, zones are created that are represented by the network ID of a subnet range in reverse. For example, if you have a network ID of 192.168.100.0 the reverse lookup zone for this domain would be 100.0.168.192._____

in-addr.arpa (answer for both blanks)

Reverse lookup DNS zone

Maps IP addresses to host names

Alias records

Used to create an alias for a specific host

Zones

Building blocks for creating your DNS infrastructure

Referral

An answer provided to the client of a different DNS server that can provide a better answer. When it receives a referral it contacts the referred DNS server for the same information.

All clients, whether they are windows vista desktop or windows server 2008 domain controllers, act as ____.

DNS clients (Note: DNS clients are often referred to as DNS resolvers.)

DNS suffix

DNS domain appended to all unqualified name queries, or a query that contains only a host name

DNS records can be resolved with ____

NSLookup

Information in a DNS record

Owner, Time-to-Live (TTL) Class, Type Resource Record Data (RDATA)

The first DNS server in the list is called the ____. It is the first DNS server your client accepts to query.

Preferred Server

Root hints

Provide IP address pointers to top-level DNS servers When configured, a DNS server can perform queries when it receives domain name requests for zones in which it is not authoritative Provide referral answers to queries in a DNS server's quest to resolve an unknown domain name request

Host (A) record

Provides host name-to-IP address resolution for DNS clients

Recursive queries

Queries where the client requires an answer from its DNS server

Secondary DNS zone

Read-only version of the DNS records for a zone

Pointer records

Resolves IP address to host names for DNS clients

The current DNS system does not support every character on the modern keyboard. DNS has a particular naming convention that must be followed. when making a new public domain you can use any of the following characters:

Uppercase or Lower case letters (A-Z) Numbers Hyphen (-) (Note: in addition to these characters, microsoft DNS reserves the underscore ( _ ) for its active directory services.

zone.dns

Used to store DNS records Found in the %systemroot%\system32\DNS folder

With root hints configured DNS can ___

perform queries when it receives domain name requests for zones in which it is not authoritative.

*following are the options you can use to manage on the DNS tab of the advanced TCP/IP settings dialog box* Append these DNS suffixes (in order) -

when this option is selected all queries use the DNS queries as listed. Remeber that the suffixes are used in order and that you can change them using the up and down arrow buttons.

DNS zones fall under two catagories :

standard and Active Directory. ( Note:the environment you are deploying to the features you need DNS to determine the types of zone you will use.)

When the DNS server requests that the forwarder provide a recursion or the best answer for its request, this allows you to offload a large amount of DNS query tasks to a server designed specifically for the purpose of providing DNS information and shift the additional workload ofiterative queries from your WAN connection, preserving valuable bandwidth. You can use the dnscmd to configure forwarders. *forwarders are defined per server and can be added through the DNS console*

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Iterative query

A DNS client requests the best answer that its DNS server can provide

___are the building of DNS infrastructure. They are classified in three ways: the information they store, where they are stored, and their read/write status.

Zones

In windows networking a ___ represents an administrative structure used to logically manage and represent a network of computing devices. It uses a similar hierarchical structure such as DNS in organizing its resources.

domain

Another option for querying is to use forwarders. Forwarders use servers to resolve names. They address one or more DNS servers that a DNS server queries when it receives a domain name request for zone in which it is not authoritative. Other servers can use forwarder to increase efficiency or security when resolving names. Example, companies often set up forwarders to the DNS servers of their internet service providers (ISPs). Contrast this with root hints, which provide referral so that a DNS server perform the Iterative query process. DNS servers request that the forwarders provide a recursion or the best answer for the request.

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Hosts

A computer on the Internet that provides a specific resource

DNS

A role that can be installed on Windows Server 2008 Full and Server Core versions

*following are the options you can use to manage on the DNS tab of the advanced TCP/IP settings dialog box* Use this connection's DNS suffix in DNS registration -

After checking this option, the computer uses DNS dynamic update to register the connection specific domain name and the IP addresses. The connection-specific DNS name is is created by appending the computer name and the DNS suffix for the connection.the computer name is the first portion of the full computer name specified on the computer name tab. When the register this connection's addresses in DNS check box is selected as well, this registration is performed in addition to the registration of the full computer name.

Forward lookup DNS zones

Allow a DNS client to resolve an FQDN to an IP address

___ are stored on DNZ servers. this makes a DNS server authoritative for the ___ it hosts

DNS Zones --- zones

Any computer that requires a host name-to-IP address resolution is a _____

DNS client

DNS records

DNS uses records to provide the information it stores in its database

____ is the process by which part of a domain namespace is placed(or ____ )to its own DNS zone. The new zone has its own authoritative DNS server responsible for its records only. For example, when a large multidomain company splits up its domain space for easier management by administrators in a different location can use ____. Large companies with separate IT staffs for different parts of the domaincan use multiple zones as well.

Delegation ------ Delegated ------ Delegation

DNS Servers

For a client to resolve DNS queries, it needs to know which server to contact. that's where the preferred and alternate DNS servers come in. Your windows DNS client can be set to use one or more DNS servers for name resolution.

Slave server

Gets its updates from the master zone transfer partner specified on the Zone Transfer tab in DNS

Name server (NS) record

Identifies a DNS server that is authoritative for a zone

Zone transfers from the master to the secondary server come in two varieties

Incremental zone transfers (IXFRs) Full zone transfers (AXFRs)

DNS clients

Often referred to as DNS resolvers First DNS server in the list is called the preferred DNS server

The ____ is hosted on a DNS server hosting a writable copy of the zone.dns file, so any changes to DNS records musty be completed at the primary zone.

Primary Zone (Note: you can only have one primary zone in a DNS structure even if you have multiple DNS servers. If there are multiple DNS servers on a network, the server holding the primary DNS zone acts as a master for replicating changes via zone transfers.)

Domain Name System

Primary function is to translate human-readable host names Assists the flow of e-mail Provides mail exchanger records that tell a Simple Mail Transfer Protocol (SMTP) server where to send an e-mail message Supported on the Internet by thousands of distributed servers, or DNS servers

Most environments use a combination of iterative and recursive queries in the DNS process. Often desktop clients and non-DNS servers perform ____ queries of their preferred or alternate DNS servers. the DNS servers then perform the ____ queries to get information they need to provide their clients.

Recursive --- Iterative

With ___ you can implement as many Secondary DNS zone servers as you need to provide effective name resolution on your network.Servers holding a secondary zone point to a master server(either primary or another secondary server) for requesting updates.

Secondary DNS Zones

Cache-only DNS server

Server that has the DNS role installed Does not hold a DNS zone so it is not authoritative for any DNS zones

Primary DNS zone

The zone that is authoritative for a specific domain and its name records

*following are the options you can use to manage on the DNS tab of the advanced TCP/IP settings dialog box* Register this connection's addresses in DNS -

after checking this option, the computer accepts dynamic DNS registration with the full computer name and IP addresses. the full computer name is specified on the Computer Name tab of the system properties dialog box.

For configuring DNS from the command line in both versions of windows server 2008 you can use the dnscmd utility. dnscmd utility allows you to ___

manage all the DNS server configuarion and management settings from the command prompt. or a script. (Note: this is perfect for server core installations)

*The DNS Namesspace is organized into the following domains* Top-Level domain (TLD):

one in the group of centrally managed domains created to differentiate the types of internet domains, these domains are managed by organizations called domain name registrars. Examples of top-level public internet domains include .com .net and .gov. Nonstandard top-level domains can be used when creating a domain, but they are generally for internet use only because they are not accessible on public internet.

DNS domains

represents a portion of the namespace to the right of the host name. For example server01.quizlet.net is a fully qualified domain name for a host called server01 in the quizlet.net DNS domain. Its made up of two parts. The first part is the top-level domain, such as .com or .net. The next part is the second level domain such as quizlet. Together they represent quizlet's public domain name -quizlet.net- which can be used for connecting with public resources attached to the domain name.

*standard dns zone types* Standard, or file-based, DNS zones fall into three different scopes:

Primary, Secondary and Stub. (Note: the scope of the DNS zones determines how it stores its records and provides name resolution to DNS client requests.)

*following are the options you can use to manage on the DNS tab of the advanced TCP/IP settings dialog box* Append primary and specific DNS suffixes -

when thsi option is selected, all queries use the primary DNS suffix and the connection specific suffix. You configure the primary DNS suffix by clicking Change on the Computer Name tab of the System Properties dialog box, and then click More on the Computer Name/Domain Changes dialog box.

If the Preferred DNS server does not respond, the DNS client refers to its list of ____ one at a time. However if the preferred server responds without being able to resolve the name request., clients DO NOT query the _____. they simply fail in their query.

alternate DNS servers (answer for both) (Note: You can now only enter two DNS servers (one preferred and one alternate) on the general tab of a dialog box for network adapter IP properties.

DNS Zones

consists of a collection of connected nodes served by an authoritative DNS name server. A zone can be a single domain namespace such as quizlet.com or it could bve multiple domains in a contiguous namespace. For example, quizlet.com for all the domain namespeces it contains. A contiguous namespace is a requirement for having multiple domains in one zone. Although you may have multiple domains within a single zone, you often need to spilt a large zone into two administrative units.

Reverse Lookup Zone

performs that opposite action of a forward lookup zone. It maps IP addresses to host names. for example, a server might receive a malicious packet from an unidentified source . Withe the reverse lookup query, the server requests the host name of the sebder based on source IP address in the packet. reverse lookup zones are less commonly used. Uses of reverse lookup zones include varification of SMTP server's name.

A ___ is authoritative for a specific domain and its name records.

primary zone

Reverse Lookup Zones are contained within a

special domain called the in-addr.arpa domain. (Note: For IPv4 and IPv6.arpa in internet protocol version 6 (IPv6). Sub-domains in the in-addr.arpa zoneare configured using the octets in dotted quads of each network ID. Each octet is reversed in the naming of each zone.

DNS suffix

the DNS domain that is appended to all unqualified name queries or query that only contains a host name. for example, suppose you have a sever called sever02.quizlet.local on your network. You could use a ping server02 command to perform name resolution by appending the domain suffix quizlet.local. Why is this important? Especially in environments with multiple domains, adding domain suffixes can ease the burden of communicating with clients in other domains without fully qualifying the name. For example, suppose quizlet.net purchases called quizwiz.biz. Both network structures are connected However you are going to maintain both domain names. So that client in the quizlet.net can more easily resolve quizwiz.biz as a DNS domain for your request when the request using quizlet.net fails.

*The DNS Namesspace is organized into the following domains* Sub-domain:

this facilitates the distribution of DNS databases and records across thousands of servers.

*installing cache-only DNS servers* A cache-only DNS server is a server that has the DNS role installed. However it does not hold a DNS zone, so it is not authoritative for any DNS zones, nor does it maintain any DNS records. It simply acts as a intermediary for DNS clients in resolving DNS queries. Using the caching functionality of DNS, a cache-only server provides clients with query answers and stores the answers in case other clients request the same information. Cache-only DNS servers are a good option for workgroup environments that want to centralize DNS requests through a single server. This optimizes the usage of an organization's wide area network (WAN) connection.

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To change the DNS suffix, open the TCP/IP properties dialog box, click advanced to display the advanced TCP/IP settings dialog box, click the advanced TCP/IP Settings dialog box and then click the appropriate add button to open the DNS suffix and NetBIOS computer name dialog box.

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*DNS Queries in Windows Servers 2008*

At the heart of the name resolution is the DNS query process. In order for DNS clients and DNS servers to interact, they need to be able to query for or request information from each other.

___ is the industry standard of DNS servers on the internet and networks running DNS on UNIX/LINUX systems.

BIND (Note: Active Directory supports the use of BIND for DNS in BIND versions 8.2.2 and later. This alows for more usage of SRV records and dynamic updates.)

*standard zones* Known as file based or file backed zones, standard zones use a file called zone.dns. This is a text based document that can be viewed in Notpad or text editors. It is formatted for compatibility with____

Berkeley Internet Name Domain (BIND) servers.

DNS zones

Classified in three ways The information they store Where they are stored Their read/write status (Stored by 2 methods Standard and Active Directory)

DNS zone

Collection of connected nodes served by an authoritative DNS name server

When configuring a DNS client, you can use the following settings, which provide the DNS client with access to DNS servers, and provide information used by the DNS client to properly perform DNS queries:

DNS servers DNS suffix

DNS Records

DNS uses records to provide information it stores in its database. A and AAAA records are the main records stored in a DNS database. Additional records containing information about directory services and e-mail are also configured in DNS records.

___ can be created after the DNS role is installed through the DNS console or command line.

DNS zones

The DNS console allows you to create ___ and manage ____ settings.

DNS zones ------ DNS server

Host name

Name given to a computer, or host, to make connecting to it easier

Stub zone

Read-only copy of a zone that obtains its resource records from the name servers that are authoritative for a particular zone

Start of Authority (SOA)

Record is the starting point for information related to a zone

Host (AAAA) Records for IPv6

Records map a host name to an IPv6 address

In order for a __ to become active, it must have access to the master records so it can perform zone transfers only to servers that are specified as name servers for the zones either by being listed on the Zone's Name Servers tab or by having a name server record created for it. Along with the default setting, you can deny all zone transfers, allow zone transfers to all servers (not recommended) or specify IP addresses of servers needing zone transfers.

Secondary DNS Zone (Note: These options are configured on the Zones Transfer tab on the properties dialog box for the zone.)

A ___ is a read-only version of the dns records for a zone. For improving performance, balancing load, and redundancy, you might need to deploy multiple DNS servers within your organization.

Secondary DNS Zones

Fully Qualified Domain Name

Server01.quizlet.net. www.quizlet.net, and remote.quizlet.net are all Fully Qualified Domain Names (FQDN) An FQDN represents the entire name for a specific host, or the dns name, that needs to have a dns record created. Users can then use the FQDN to get the host IP address. each part of the domain name is referred to as a label, is separated by a decimal point (.) FQDNs are created by appending the host name label of a computer to a DNS domain name, sometimes referred to as a DNS suffix, that contains the computer.for example suppose you have a server called webserver01 that needs to be available from the internet so your users can acces the corporate website. You have purchased the domain name Mycorporation.net as your public domain name.when users need to access your server from the internet, they type webserver01.mycorporation.net into their web browser and then your website is displayed to them.

A ___ is a read-only copy of a zone that obtains its resource records from the name servers that are authoritative for the particular zone. Unlike the secondary zone, this type of zone contains only the following resource records for a zone: Start of authority record of the zone name server (NS) records for all name servers authoritative for the zone Host(A) records for all name servers authoritative for the zone.

Stub Zone (Note: this reduces the size of the stub zone's database, which is a major advantage of using stub zones. Stub zones can help reduce the amount of DNS traffic on your network by streamlining name resolution and zone replication. Instead of a master server having to replicate all of its records to a secondary server across a WAN link, you can set up a stub zone.)

When DNS is installed on an internet-connected server, it ___

configures the IP addresses for referral servers for the root domain. (Note: these servers are known as root hints)

Recursive Queries

queries where the client requires an answer from its DNS server. In this case it receives a positive or negative answer. the client either receives the resolved address or is told it cannot be resolved, and no answer is given to the client.

root hints provide ____ to queries in a DNS server's quest to solve an unknown domain name request

referral answers (Note: the purpose of root hints servers is to resolve the common top level domains such as .net, .com, and .gov. Acces to the internet is required to use root hints. The root hints installed on a windows server 2008 DNS server is based on a list of common root domain DNS servers.This list is defined in the file called cache.dns)

DNS Namespace

the backbone of the dns structure is the concept of dns namespace. The dns namespace is a top-down hierarchical structure based on domain names. As you move down the branches of the hierarchy, one or more nodes or hosts hold resource records that contain details about a specific portion of the domain name.

*The DNS Namesspace is organized into the following domains* Second-Level domain

this level is most denotes the company or organization name associated with the domain. for example, www.quizlet.com, quizlet would be the second level domain registered with a domain registrar in the .net top level domain.

*following are the options you can use to manage on the DNS tab of the advanced TCP/IP settings dialog box* DNS suffix for this connection -

when this option is filled in, it is used in addition to the two previous options. This value can be asigned via DHCP, set manually on the local machine or it can be defined via group policy. the Local Machine setting and group policy override any value delivered via DHCP.

Iterative Queries

With an Iterative Query, a DNS client requests the best answer that its DNS server can provide. This means if the DNS server has the anser cached or is not authoritative for the zone, it provides the host client with a referral.

Hosts

a computer on the internet that provides a specific resource is called a host. This host is often a web server responsible for supplying web based information or applications. Hosts can also be network entry points for a company's network such as a firewall or router. In DNS hosts are identified by creation of an A record. Prior implementation of DNS computers used a file called Hosts for name resolution.

Host Name

a host name is a name given to a computer, or host, to make connecting to it easier. Instead of typing a long IP address, you can enter the host name followed by the domain name such as myhost name.no-ip.com. host names are recordrd in DNS through the caretion of an A record that maps the host name to the Ip address.

Unlike the other properties for a network adapter, Server Core does not support changing the DNS suffix with netsh. You have two options:

If you server core installation is a member of a domain, you can use group policy to apply DNS suffix. the next option is to edit the registry using regedit.exe, another GUI tool that is available in server core.

Berkeley Internet Name Domain (BIND)

Industry standard of DNS servers on the Internet and networks running DNS on UNIX/Linux systems

There are two types of queries in the DNS query process:

Iterative queries AND Recursive queries

Service locator records Provides the following information:

Location of services it needs Network protocol needed to access the previously mentioned services Domain services it provides

When a master server needs to resolve DNS information from the zone represented by a stub zone, it queries NS servers listed in its zone. Like all DNS servers this information is cached for future queries. For example, suppose you have two companies that want to share DNS information between quizlet.net and quizwiz.biz. These companies are connected over a WAN connection, so you need to minimize the traffic that flows between the two servers. The administrator in quizlet.net can create a stub zone that points to the name servers in quizwiz.biz without having to resort to iterative queries.

(note card) (Extra Note:another advantage to stub zones is that they can be integrated into Active Directory and be replicated as part of Active Directory replication. Standard secondary servers cannot.)

*Dynamic Updates* windows clients that support dynamic updates will automatically create host and reverse lookup records for themeselvves on DNS servers supporting dynamic updates.windows server 2008 supports dynamic updates with both standard and active directory domain services integrated domains. Dynamic Updates are sometimes referred to as DDNS.

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*Installing DNS in windows server 2008* DNS is a role that can be installed on windows server 2008 full and server core versions. Often DNS is combined with other services such as DHCP or in the case of Active Directory Integrated DNS, it is combined it is combined with a domain controller.

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