Interview questions for windows server 2008 administrator

In the same folder, you can also see other files; these are the main files controlling the AD structures they are. Lingering objects can exists if a domain controller does not replicate for an interval of time that is longer than the tombstone lifetime TSL. Tombstone lifetime in an Active Directory determines how long a deleted object is retained in Active Directory. Usually, windows will use a day tombstone lifetime if time is not set in the forest configuration.

Schema is an active directory component describes all the attributes and objects that the directory service uses to store data. Infrastructure Master is accountable for updating information about the user and group and global catalogue. IntelliMirror helps to reconcile desktop settings, applications and stored files for users especially for those users who move between workstations or those who works offline. To add the application using the Software Installer. ZAP text file can be used rather than the windows installer.

Even if the group policy is changed or removed, the user preference will still persist in the registry. Primary function of the domain controller is to validate users to the networks, it also provide a catalog of Active Directory Objects. To configure the DHCP server, you can create a reservation for the device.

To create a reservation, you must know the MAC hardware address of the device. To determine the MAC address for a network device you can use the ipconfig or nbs tat command line utilities. To look up for the information from the server, e-mail and another program follows or uses the internet protocol. It is a set of files and folders that is stored on the local hard disk of each domain controller in a domain and are replicated by the FRS File Replication Service.

Usually, windows will use a day tombstone lifetime if time is not set in the forest configuration. Schema is an active directory component describes all the attributes and objects that the directory service uses to store data. Infrastructure Master is accountable for updating information about the user and group and global catalogue. The exchange management console is well designed Recycle bin goes GUI: In windows server 12, there are now many ways to enable the active directory recycle bin through the GUI in the Active Directory Administrative Center, which was not possible with the earlier version Fine grained password policies FGPP : In windows server 12 implementing FGPP is much easier compared to an earlier It allows you to create different password policies in the same domain Windows Power Shell History Viewer: You can view the Windows PowerShell commands that relates to the actions you execute in the Active Directory Administrative Center UI 3 Mention which is the default protocol used in directory services?

Enterprise Admin Group Domain Admin Group Members of this group have complete control of all domains in the forest By default, this group belongs to the administrators group on all domain controllers in the forest As such this group has full control of the forest, add users with caution Members of this group have complete control of the domain By default, this group is a member of the administrators group on all domain controllers, workstations and member servers at the time they are linked to the domain As such the group has full control in the domain, add users with caution 7 Mention what system state data contains?

In the same folder, you can also see other files; these are the main files controlling the AD structures they are dit log res 1. This automation tool is greatly helpful for executing a typical management task. Besides, this power shell includes adding and deleting accounts, editing groups, and creating a list to view specific types of users or groups.

Besides, this powerful tool has an integrated scripting environment ISE , a graphic user interface that lets you run commands and create or test scripts. This interface lets you develop the scripts such as command collection, where you can add the logic for execution.

This is particularly useful for system administrators who need to run the command sequences for system configuration.

Likewise, there are multiple uses of power shell in the real-time industry. By reaching the end of this article, I hope you people have gained the best knowledge on power shell. You people can get more practical knowledge on PowerShell taught by real-time experts at power shell online Course. In the upcoming articles of this blog, I'll be sharing the details of more information on PowerShell.

Define what is Active Directory? Answer: Active Directory is a Meta Data. Active Directory is a data base which store a data base like your user information, computer information and also other network object info. It has capabilities to manage and administrate the complete Network which connect with AD. Answer: Domain local groups assign access permissions to global domain groups for local domain resources.

Universal groups grant access to resources in all trusted domains. I am trying to create a new universal user group. Answer: Universal groups are allowed only in native-mode Windows Server environments. Native mode requires that all domain controllers be promoted to Windows Server Active Directory. What is an IP address?

Answer: Every device connected to the public Internet is assigned a unique number known as an Internet Protocol IP address. IP addresses consist of four numbers separated by periods also called a 'dotted-quad' and look something like In computer networking, an Internet Protocol IP address consists of a numerical identification logical address that network management assigns to devices participating in a computer network utilizing the Internet Protocol for communication between its nodes.

The role of the IP address has been characterized as follows: "A name indicates what we seek. An address indicates where it is. A route indicates how to get there. What is subnet Mask? Answer: A subnet short for "subnetwork" is an identifiably separate part of an organization's network.

Typically, a subnet may represent all the machines at one geographic location, in one building, or on the same local area network LAN.

Having an organization's network divided into subnets allows it to be connected to the Internet with a single shared network address. Without subnets, an organization could get multiple connections to the Internet, one for each of its physically separate subnetworks, but this would require an unnecessary use of the limited number of network numbers the Internet has to assign. It would also require that Internet routing tables on gateways outside the organization would need to know about and have to manage routing that could and should be handled within an organization.

What is ARP? In an Ethernet local area network, however, addresses for attached devices are 48 bits long. ARP provides the protocol rules for making this correlation and providing address conversion in both directions. How ARP Works? Answer: When an incoming packet destined for a host machine on a particular local area network arrives at a gateway , the gateway asks the ARP program to find a physical host or MAC address that matches the IP address.

The ARP program looks in the ARP cache and, if it finds the address, provides it so that the packet can be converted to the right packet length and format and sent to the machine.

If no entry is found for the IP address, ARP broadcasts a request packet in a special format to all the machines on the LAN to see if one machine knows that it has that IP address associated with it. A machine that recognizes the IP address as its own returns a reply so indicating. Define what is Active Directory Domain Services? Define what is domain? The user need only to log in to the domain to gain access to the resources, which may be located on a number of different servers in the network.

Define what is domain controller? Answer: A Domain controller DC is a server that responds to security authentication requests logging in, checking permissions, etc.

A domain is a concept introduced in Windows NT whereby a user may be granted access to a number of computer resources with the use of a single username and password combination.

What is a default gateway? What happens if I don't have one? Answer: a gateway is a routing device that knows how to pass traffic between different subnets and networks. A computer will know some routes a route is the address of each node a packet must go through on the Internet to reach a specific destination , but not the routes to every address on the Internet. It won't even know all the routes on the nearest subnets. A gateway will not have this information either, but will at least know the addresses of other gateways it can hand the traffic off to.

Your default gateway is on the same subnet as your computer, and is the gateway your computer relies on when it doesn't know how to route traffic. The default gateway is typically very similar to your IP address, in that many of the numbers may be the same. However, the default gateway is not your IP address.

To see what default gateway you are using, follow the steps below for your operating system. What is a subnet? Answer: In computer networks based on the Internet Protocol Suite, a subnetwork, or subnet, is a portion of the network's computers and network devices that have a common, designated IP address routing prefix cf.

A routing prefix is the sequence of leading bits of an IP address that precede the portion of the address used as host identifier or rest field in early Internet terminology. What is an RFC? Name a few if possible not necessarily the numbers, just the ideas behind them What is RFC ? Efforts are in progress within the community to find long term solutions to both of these problems. Meanwhile it is necessary to revisit address allocation procedures, and their impact on the Internet routing system.

What is CIDR? For example: CIDR addresses reduce the size of routing tables and make more IP addresses available within organizations. CIDR is also called supernetting. You have the following Network ID: What is the IP range for your network? Answer: You need at least hosts per network. How many networks can you create?

What subnet mask will you use? You need to view at network traffic. What will you use? Name a few tools? Answer: Monitoring network traffic tool Q.

How do I know the path that a packet takes to the destination? Answer: use "tracert" command-line Q. What does the ping Answer: The ping command will send roundtrip packets to a destination other PC, router, printer, etc. The The -l is how big the packet should be in bytes. The default is 32, if the -l parameter is not used.

And the -n is saying to send, it times. The default is 4, when this parameter is not used. What is DHCP? What are the benefits and drawbacks of using it? In a networked environment it is a method to assign an 'address' to a computer when it boots up. Benefit: A system administrator need not worry about computers being able to access networked resources Q. Also, DHCP helps prevent address conflicts caused by a previously assigned IP address being reused to configure a new computer on the network.

Reduces configuration management Using DHCP servers can greatly decrease time spent configuring and reconfiguring computers on your network. Servers can be configured to supply a full range of additional configuration values when assigning address leases. These values are assigned using DHCP options. Also, the DHCP lease renewal process helps assure that where client configurations need to be updated often such as users with mobile or portable computers who change locations frequently , these changes can be made efficiently and automatically by clients communicating directly with DHCP servers.

Answer: HCP uses a client-server model. The server database includes the following: Valid configuration parameters for all clients on the network. Valid IP addresses maintained in a pool for assignment to clients, plus reserved addresses for manual assignment. Duration of a lease offered by the server. The lease defines the length of time for which the assigned IP address can be used. With a DHCP server installed and configured on your network, DHCP-enabled clients can obtain their IP address and related configuration parameters dynamically each time they start and join your network.

DHCP servers provide this configuration in the form of an address-lease offer to requesting clients. Name 2 scenarios.? Answer: Open Windows Components Wizard.

Under Components, scroll to and click Networking Services. Click Details. If prompted, type the full path to the Windows Server distribution files, and then click Next. Required files are copied to your hard disk. In the console tree, click DHCP. On the Action menu, click Manage authorized servers. The Manage Authorized Servers dialog box appears.

Click Authorize. Active directory interview questions Q. Similarly, changing authorization rights for a particular user on a group of devices has meant visiting each one and making configuration changes. DHCP integration with DNS allows the aggregation of these tasks across devices, enabling a company's network services to scale in step with the growth of network users, devices, and policies, while reducing administrative operations and costs.

This integration provides practical operational efficiencies that lower total cost of ownership. Creating a DHCP network automatically creates an associated DNS zone, for example, reducing the number of tasks required of network administrators. This is usually done during the bootstrap process when a computer is starting up. DNS zones — describe the differences between the 3 types. A DNS server resolves a name to an IP address, as stated in an earlier answer, but it can also point to multiple IP addresses for load balancing, or for backup servers if one or more is offline or not accepting connections.

Individual organizations may have their own DNS servers for their local Intranet. Some sites have their own DNS server to switch between subdomains within them. For example, a site such as Blogspot can have subdomains come and go quite frequently. Rather than force every DNS server to update their own databases whenever someone creates a new blog, Blogspot could maintain their own DNS server to resolve names within the blogspot. The following are the three main components of DNS: Domain name space and associated resource records RRs A distributed database of name-related information.

This authoritative information is organized into units called zones, which are the main units of replication in DNS. The following are the three DNS zone types implemented in Windows Standard Primary Holds the master copy of a zone and can replicate it to secondary zones. All changes to a zone are made on the standard primary. Standard Secondary Contains a read-only copy of zone information that can provide increased performance and resilience. Information in a primary zone is replicated to the secondary by use of the zone transfer mechanism.

DNS record types — describe the most important ones. TTL The length of time used by other DNS servers to determine how long to cache information for a record before discarding it. For most RRs, this field is optional. This prevents these records from being cached by other DNS servers for a longer period, which would delay the propagation of changes.

Class For most RRs, this field is optional. Where it's used, it contains standard mnemonic text indicating the class of an RR. Type This required field holds a standard mnemonic text indicating the type for an For example, a mnemonic of A indicates that the RR stores host address information. Record-Specific Data This is a variable-length field containing information describing the resource.

This information's format varies according to the type and class of the RR. Describe the process of working with an external domain name Answer: If it is not possible for you to configure your internal domain as a subdomain of your external domain, use a stand-alone internal domain. This way, your internal and external domain names are unrelated. For example, an organization that uses the domain name contoso.

The advantage to this approach is that it provides you with a unique internal domain name. The disadvantage is that this configuration requires you to manage two separate namespaces. Also, using a stand-alone internal domain that is unrelated to your external domain might create confusion for users because the namespaces do not reflect a relationship between resources within and outside of your network.

In addition, you might have to register two DNS names with an Internet name authority if you want to make the internal domain publicly accessible. Answer: When Microsoft began development on Active Directory, full compatibility with the domain name system DNS was a critical priority.

Active Directory was built from the ground up not just to be fully compatible with DNS but to be so integrated with it that one cannot exist without the other. Microsoft's direction in this case did not just happen by chance, but because of the central role that DNS plays in Internet name resolution and Microsoft's desire to make its product lines embrace the Internet.

When Microsoft began development on Active Directory, full compatibility with the domain name system DNS was a critical priority. On the Advanced tab you will find the confusingly similar option Disable recursion also disables forwarders. So what is the difference between these settings? The DNS server will attempt to resolve the name locally, then will forward requests to any DNS servers specified as forwarders.

If Do not use recursion for this domain is enabled, the DNS server will pass the query on to forwarders, but will not recursively query any other DNS servers e. If Disable recursion also disables forwarders is set, the server will attempt to resolve a query from its own database only. It will not query any additional servers. If neither of these options is set, the server will attempt to resolve queries normally: the local database is queried if an entry is not found, the request is passed to any forwarders that are set if no forwarders are set, the server will query servers on the Root Hints tab to resolve queries beginning at the root domains.

What is a "Single Label domain name" and what sort of issues can it cause? Answer: Single-label names consist of a single word like "contoso". Single-label DNS names cannot be registered by using an Internet registrar. Client computers and domain controllers that joined to single-label domains require additional configuration to dynamically register DNS records in single-label DNS zones. By default, Windows Server based domain members, Windows XP-based domain members, and Windows based domain members do not perform dynamic updates to single-label DNS zones.

Some server-based applications are incompatible with single-label domain names. Application support may not exist in the initial release of an application, or support may be dropped in a future release. Some server-based applications are incompatible with the domain rename feature that is supported in Windows Server domain controllers and in Windows Server domain controllers.

These incompatibilities either block or complicate the use of the domain rename feature when you try to rename a single-label DNS name to a fully qualified domain name. What is the "in-addr. This article explains this process. The following is quoted from RFC "The Internet uses a special domain to support gateway location and Internet address to host mapping.

Other classes may employ a similar strategy in other domains. The intent of this domain is to provide a guaranteed method to perform host address to host name mapping, and to facilitate queries to locate all gateways on a particular network on the Internet. ARPA suffix. Each label represents one octet of an Internet address, and is expressed as a character string for a decimal value in the range with leading zeros omitted except in the case of a zero octet which is represented by a single zero.

For example, if you have a network which is Any hosts with IP addresses in the ARPA file may contain entries for hosts in many domains. Consider the following scenario. There is a Reverse Lookup file ARPA with the following contents: Exp : 1. Answer: When you install Active Directory on a member server, the member server is promoted to a domain controller.

Active Directory uses DNS as the location mechanism for domain controllers, enabling computers on the network to obtain IP addresses of domain controllers.

During the installation of Active Directory, the service SRV and address A resource records are dynamically registered in DNS, which are necessary for the successful functionality of the domain controller locator Locator mechanism.

To find domain controllers in a domain or forest, a client queries DNS for the SRV and A DNS resource records of the domain controller, which provide the client with the names and IP addresses of the domain controllers. If the server does not support the required standards, or the authoritative DNS zone cannot be configured to allow dynamic updates, then modification is required to your existing DNS infrastructure.

For more information, see Managing resource records. Name 3 benefits of using AD-integrated zones. When you configure a computer as a DNS server, zones are usually stored as text files on name servers that is, all of the zones required by DNS are stored in a text file on the server computer. These text files must be synchronized among DNS name servers by using a system that requires a separate replication topology and schedule called a zone transfer However, if you use Active Directory—integrated DNS when you configure a domain controller as a DNS name server, zone data is stored as an Active Directory object and is replicated as part of domain replication.

Active Directory—integrated zones enable you to store zone data in the Active Directory database. Zone information about any primary DNS server within an Active Directory— integrated zone is always replicated. In an Active Directory—integrated zone, a primary DNS server cannot be a single point of failure because Active Directory uses multimaster replication.

Updates that are made to any domain controller are replicated to all domain controllers and the zone information about any primary DNS server within an Active Directory—integrated zone is always replicated. Active Directory—integrated zones: Enable you to secure zones by using secure dynamic update. Provide increased fault tolerance. Every Active Directory—integrated zone can be replicated to all domain controllers within the Active Directory domain or forest.

All DNS servers running on these domain controllers can act as primary servers for the zone and accept dynamic updates. Enable replication that propagates changed data only, compresses replicated data, and reduces network traffic. If you have an Active Directory infrastructure, you can only use Active Directory—integrated zones on Active Directory domain controllers.

If you are using Active Directory—integrated zones, you must decide whether or not to store Active Directory—integrated zones in the application directory partition. You can combine Active Directory—integrated zones and file-based zones in the same design.

For example, if the DNS server that is authoritative for the private root zone is running on an operating system other than Windows Server or Windows , it cannot act as an Active Directory domain controller.

Therefore, you must use file-based zones on that server. However, you can delegate this zone to any domain controller running either Windows Server or Windows Name a few possible causes. What are the benefits and scenarios of using Stub zones?

Answer: Understanding stub zones A stub zone is a copy of a zone that contains only those resource records necessary to identify the authoritative Domain Name System DNS servers for that zone.

A stub zone is used to resolve names between separate DNS namespaces. This type of resolution may be necessary when a corporate merger requires that the DNS servers for two separate DNS namespaces resolve names for clients in both namespaces. A stub zone consists of: The start of authority SOA resource record, name server NS resource records, and the glue A resource records for the delegated zone. The IP address of one or more master servers that can be used to update the stub zone.

The master servers for a stub zone are one or more DNS servers authoritative for the child zone, usually the DNS server hosting the primary zone for the delegated domain name. Using stub zones Updated: January 21, Using stub zones Use stub zones to Keep delegated zone information current. By updating a stub zone for one of its child zones regularly, the DNS server hosting both the parent zone and the stub zone will maintain a current list of authoritative DNS servers for the child zone.

Improve name resolution. Stub zones enable a DNS server to perform recursion using the stub zone's list of name servers without needing to query the Internet or internal root server for the DNS namespace.

Simplify DNS administration. By using stub zones throughout your DNS infrastructure, you can distribute a list of the authoritative DNS servers for a zone without using secondary zones. However, stub zones do not serve the same purpose as secondary zones and are not an alternative when considering redundancy and load sharing. There are two lists of DNS servers involved in the loading and maintenance of a stub zone: The list of master servers from which the DNS server loads and updates a stub zone.

A master server may be a primary or secondary DNS server for the zone. In both cases, it will have a complete list of the DNS servers for the zone. This list is contained in the stub zone using name server NS resource records. When a DNS server loads a stub zone, such as widgets. The list of master servers may contain a single server or multiple servers and can be changed anytime.

For more information, see Configure a stub zone for local master servers. What are the benefits and scenarios of using Conditional Forwarding? Answer: Rather than having a DNS server forward all queries it cannot resolve to forwarders, the DNS server can forward queries for different domain names to different DNS servers according to the specific domain names that are contained in the queries. Forwarding according to these domain-name conditions improves conventional forwarding by adding a second condition to The forwarding process.

A conditional forwarder setting consists of a domain name and the IP address of one or more DNS servers. When a DNS client or server performs a query operation against a Windows Server based DNS server that is configured for forwarding, the DNS server looks to see if the query can be resolved by using its own zone data or the zone data that is stored in its cache, and then, if the DNS server is configured to forward for the domain name that is designated in the query a match , the query is forwarded to the IP address of a DNS Server that is associated with the domain name.

If the DNS server has no domain name listed for the name that is designated in the query, it attempts to resolve the query by using standard recursion. Answer: Cluster technologies are becoming increasingly important to ensure service offerings meet the requirements of the enterprise. Windows and Windows Server support three cluster technologies to provide high availability, reliability and scalability.

These technologies have a specific purpose and are designed to meet different requirements. Server cluster provides failover support for applications and services that require high availability, scalability and reliability, and is ideally suited for back-end applications and services, such as database servers.

Server cluster can use various combinations of active and passive nodes to provide failover support for mission critical applications and services. NLB provides failover support for IP-based applications and services that require high scalability and availability, and is ideally suited for Web tier and front-end NLB clusters can use multiple adapters and different broadcast methods to assist in the load balancing of TCP, UDP and GRE traffic requests.

CLB clusters use two clusters. The routing cluster can be configured as a routing list on the front-end Web servers or as separate servers that run Server cluster. Cluster technologies by themselves are not enough to ensure that high availability goals can be met. Multiple physical locations may be necessary to guard against natural disasters and other events that may cause complete service outage. Effective processes and procedures, in addition to good architecture, are the keys to high availability.

Round robin is a local balancing mechanism used by DNS servers to share and distribute network resource loads. You can use it to rotate all resource record RR types contained in a query answer if multiple RRs are found. This feature provides a simple method for load balancing client use of Web servers and other frequently queried multihomed computers.

If round robin is disabled for a DNS server, the order of the response for these queries is based on a static ordering of RRs in the answer list as they are stored in the zone either its zone file or Active Directory.

What is the Answer: WINS server group address. Used to support auto discovery and dynamic configuration of replication for WINS servers. What is WINS and when do we use it? The WINS server returns the destination computer's IP address to the original computer without the need for broadcast traffic.

The second reason for using WINS is that it's dynamic. As computers attach to and detach from the network, the WINS databases are updated automatically. What are the "considerations" regarding not using WINS? This ensures that a name registered with one WINS server is replicated to all other Microsoft WINS servers within the intranet, providing a replicated and enterprise-wide database. The following table describes the pull and push partner types of replication partners.

What is the difference between tombstoning a WINS record and simply deleting it? Eventually, you may many end up with a scenario where a WINS server that owns a record and its direct replication partner has a replica of the record but does not own the record. The problem occurs when no domain controllers refresh the record on the remote WINS server, the records will expire, become tombstoned, and be scavenged out of the database.

The following is an example of what could happen Q. In Microsoft Windows NT 3. Clients that are running the following versions In Windows NT 3. In this situation, the WINS client sends a request to the next server in the list. It can also be used as a communications protocol in a private network either an intranet or an extranet. The higher layer, Transmission Control Protocol, manages the assembling of a message or file into smaller packets that are transmitted over the Internet and received by a TCP layer that reassembles the packets into the original message.

The lower layer, Internet Protocol, handles the address part of each packet so that it gets to the right destination. Each gateway computer on the network checks this address to see where to forward the message. Even though some packets from the same message are routed differently than others, they'll be reassembled at the destination.

Being stateless frees network paths so that everyone can use them continuously. Note that the TCP layer itself is not stateless as far as any one message is concerned. Its connection remains in place until all packets in a message have been received. These protocols encapsulate the IP packets so that they can be sent over the dial-up phone connection to an access provider's modem. Other protocols are used by network host computers for exchanging router information.

What is NetBios? Answer: Netbios. Describe the role of the routing table on a host and on a router. Answer: In internetworking, the process of moving a packet of data from source to destination. Routing is usually performed by a dedicated device called a router.

Routing is a key feature of the Internet because it enables messages to pass from one computer to another and eventually reach the target machine. Each intermediary computer performs routing by passing along the message to the next computer. Part of this process involves analyzing a routing table to determine the best path. A device that forwards data packets along networks.

Routers are located at gateways, the places where two or more networks connect. Routers use headers and forwarding tables to determine the best path for forwarding the packets, and they use protocols such as ICMP to communicate with each other and configure the best route between any two hosts. Very little filtering of data is done through routers. Defined OSI model? In its most basic form, it divides network architecture into seven layers which, from top to bottom, are the Application, Presentation, Session, Transport, Network, Data-Link, and Physical Layers.

The Physical Layer defines the electrical and physical specifications for devices. In particular, it defines the relationship between a device and a physical medium. To understand the function of the Physical Layer in contrast to the functions of the Data Link Layer, think of the Physical Layer as concerned primarily with the interaction of a single device with a medium, where the Data Link Layer is concerned more with the interactions of multiple devices i.

The Physical Layer will tell one device how to transmit to the medium, and another device how to receive from it in most Cases it does not tell the device how to connect to the medium. Obsolescent Physical Layer standards such as RS do use physical wires to control access to the medium. Originally, this layer was intended for point-to-point and point-to-multipoint media, characteristic of wide area media in the telephone system. In modern practice, only error detection, not flow control using sliding window, is present in modern data link protocols such as Point-to-Point Protocol PPP , and, on local area networks, the IEEE Sliding window flow control and acknowledgment is used at the Transport Layer by protocols such as TCP, but is still used in niches where X.

Not all Physical Layer bits necessarily go into frames, as some of these bits are purely intended for Physical Layer functions. The Network Layer performs network routing functions, and might also perform fragmentation and reassembly, and report delivery errors. Routers operate at this layer—sending data throughout the extended network and making the Internet possible. This is a logical addressing scheme — values are chosen by the network engineer. The addressing scheme is hierarchical.

It manages the connectionless transfer of data one hop at a time, from end system to ingress router, router to router, and from egress router to destination end system. It is not responsible for reliable delivery to a next hop, but only for the detection of errored packets so they may be discarded. When the medium of the next hop cannot accept a packet in its current length, IP is responsible for fragmenting into sufficiently small packets that the medium can accept it.

These include routing protocols, multicast group management, Network Layer information and error, and Network Layer address assignment.

It is the function of the payload that makes these belong to the Network Layer, not the protocol that carries them. Some protocols are state and connection oriented.

This means that the Transport Layer can keep track of the segments and retransmit those that fail. It establishes, manages and terminates the connections between the local and remote application. It provides for full-duplex, half-duplex, or simplex operation, and establishes checkpointing, adjournment, termination, and restart procedures. The OSI model made this layer responsible for "graceful close" of sessions, which is a property of TCP, and also for session checkpointing and recovery, which is not usually used in the Internet Protocol Suite.

The Session Layer is commonly implemented explicitly in application environments that use remote procedure calls RPCs. Layer 6: Presentation Layer The Presentation Layer establishes a context between Application Layer entities, in which the higher-layer entities can use different syntax and semantics, as long as the Presentation Service understands both and the mapping between them.

The presentation service data units are then encapsulated into Session Protocol Data Units, and moved down the stack. This layer interacts with software applications that implement a communicating component. Such application programs fall outside the scope of the OSI model. Application layer functions typically include identifying communication partners, determining resource availability, and synchronizing communication.

When identifying communication partners, the application layer determines the identity and availability of communication partners for an application with data to transmit. When determining resource availability, the application layer must decide whether sufficient network resources for the requested communication exist.

In synchronizing communication, all communication between applications requires cooperation that is managed by the application layer. Define what is LDAP? What are routing protocols? Why do we need them?

Name a few. Answer: routing protocol is a protocol that specifies how routers communicate with each other to disseminate information that allows them to select routes between any two nodes on a network. Typically, each router has a prior knowledge only of its immediate neighbors. A routing protocol shares this information so that routers have knowledge of the network topology at large.

For a discussion of the concepts behind routing protocols, see: Routing. The term routing protocol may refer more specifically to a protocol operating at Layer 3 of the OSI model which similarly disseminates topology information between routers. Many routing protocols used in the public Internet are defined in documents called RFCs. There are three major types of routing protocols, some with variants: link-state routing protocols, path vector protocols and distance vector routing protocols.

The specific characteristics of routing protocols include the manner in which they either prevent routing loops from forming or break routing loops if they do form, and the manner in which they determine preferred routes from a sequence of hop costs and other preference factors.