Monday, November 10, 2008

interviw Questions ADS

1. What is Global Catalog Server?

Global Catalog server is the server which keeps the stores the details of each object created in the forest. Global Catalog is the master searchable index to all objects in forest

2. Can GC Server and Infrastructure place in single server? If not explain why?

No, As Infrastructure master does the same job as the GC. It does not work together.

3. What is the size of log file which created before updating into ntds.dit and the total number of files?

Three Log files Names

Edb.log

Res1.log

Res2.log

Each initially 10 MB

4. What does SYSVOL contains?

SysVol Folder contains the public information of the domain & The information for replication

Ex: Group policy object & scripts can be found in this directory.

5. Which is service in your windows is responsible for replication of Domain controller to another domain controller.

KCC generates the replication topology.

Use SMTP / RPC to replicate changes.

6. How data will travel between sites in ADS replication?

As determined in the site connectors

7. What is the port number for SMTP, Kerberos, LDAP, and GC Server??

SMTP 25, Kerberos 88, GC 3268, LDAP 389

8. What Intrasite and Intersite Replication?

Intrasite is the replication within the same site & intersite the replication between sites

9. What is lost & found folder in ADS?

It's the folder where you can find the objects missed due to conflict.

Ex: you created a user in OU which is deleted in other DC & when replication happed ADS didn't find the OU then it will put that in Lost & Found Folder.

10. What is Garbage collection?

Garbage collection is the process of the online defragmentation of active directory. It happens every 12 Hours.

11. What System State data contains?

Contains Startup files,

Registry

Com + Registration Database

Memory Page file

System files

AD information

Cluster Service information

SYSVOL Folder

12. How do you restore a particular OU which got deleted by accident?

Go authoritative restore

13. What is IPSec Policy?

IPSec provides secure gateway-to-gateway connections across outsourced private wide area network (WAN) or Internet-based connections using L2TP/IPSec tunnels or pure IPSec tunnel mode.

IPSec Policy can be deployed via Group policy to the Windows Domain controllers 7 Servers.

14. What are different types of Group Policy?

I don't think there are types of group policies????

15. What is the order of applying Group Policy?

Local Policy.

Site Policy.

Domain Policy.

OU Policy.

16. What are the new features in Windows 2003 related to ADS, Replication, and Trust?

ADS: Can more than 5000 users in the groups

17. How to edit the Schema in ADS?

ADSI Edit

18. What is Domain Local, Global Group, Universal group?

Domain Local – Only Users with in Domain

Global groups are used to grant permissions to objects in any domain in the domain tree or forest. Members of global groups can include only accounts and groups from the domain in which they are defined.

Universal groups are used to grant permissions on a wide scale throughout a domain tree or forest. Members of global groups include accounts and groups from any domain in the domain tree or forest.

19. Diff between Global & Universal group?

Check the answer above.

20. What are the different types of Terminal Services?

User Mode & Application Mode

21. What does mean by root DNS servers?

Public DNS servers Hosted in the Internet which registers the DNS

22. What are the different records in DNS?

A – Address record

MX – Mail Server Record

NS – Name Server

CNAME – Canonical name / Alias

SOA – Start of authority

23. What is a SOA record?

Start of authority – authorized DNS in the domain

24. How does the down-level clients register it names with DNS server?

Enable the WINS integration with DNS.

25. What is RsOP?

RsOP is the resultant set of policy applied on the object (Group Policy)

26. What is default lease period for DHCP Server?

8 days Default

27. What is the process of DHCP clients for getting the ip address?

Discover – Order – Receive - Acknowledge

28. What is multicast?

Multicast scopes enable you to lease Class D IP addresses to clients for participation in multicast transmissions, such as streaming video and audio transmissions.

29. What is superscope?

Superscope enables you to group several standard DHCP scopes into a single administrative group without causing any service disruption to network clients.

30. What is the System Startup process?

Windows 2K boot process on Intel architecture.

1. Power-On Self Tests (POST) is run.

2. The boot device is found, the Master Boot Record (MBR) is loaded into memory, and its program is run.

3. The active partition is located, and the boot sector is loaded.

4. The Windows 2000 loader (NTLDR) is then loaded.

The boot sequence executes the following steps:

1. The Windows 2000 loader switches the processor to the 32-bit flat memory model.

2. The Windows 2000 loader starts a mini-file system.

3. The Windows 2000 loader reads the BOOT.INI file and displays the operating system selections (boot loader menu).

4. The Windows 2000 loader loads the operating system selected by the user. If Windows 2000 is selected, NTLDR runs NTDETECT.COM. For other operating systems, NTLDR loads BOOTSECT.DOS and gives it control.

5. NTDETECT.COM scans the hardware installed in the computer, and reports the list to NTLDR for inclusion in the Registry under the HKEY_LOCAL_MACHINE_HARDWARE hive.

6. NTLDR then loads the NTOSKRNL.EXE, and gives it the hardware information collected by NTDETECT.COM. Windows NT enters the Windows load phases.

31. What is WINS hybrid & mixed mode?

Systems that are configured to use WINS are normally configured as a hybrid (H-node) client, meaning they attempt to resolve NetBIOS names via a WINS server and then try a broadcast (B-node) if WINS is unsuccessful. Most systems can be configured to resolve NetBIOS names in one of four modes:

Broadcast (B-node)—Clients use a broadcast only to resolve names. An enhanced B-node setting has the client use an LMHOST file as well. The hex value for this setting is 0x1.

Peer-to-Peer (P-node)—Clients use WINS only to resolve names. The hex value for this setting is 0x2.

Mixed (M-node)—Clients first use a broadcast in an attempt to resolve NetBIOS names. If this fails, they attempt the resolution via the WINS server. The hex value for this setting is 0x4.

Hybrid (H-node)—Clients first use the WINS service in an attempt to resolve NetBIOS names. If this fails, they attempt the resolution via broadcast. The hex value for this setting is 0x8.

32. What is Disk Quota?

Disk Quota is the specifying the limits of usage on the disks.

1) What is different Editions of Windows 2003 server?

i)Standard Edition

ii)Web Edition

iii)Enterprise Edition

iv)Datacenter Edition

2) What is active directory?

Active Directory is the directory service included in the Windows Server 2003 family. Active Directory includes the directory, which stores information about network resources, as well as all the services that make the information available and useful. Active Directory is also the directory service included in Windows 2000.

3)What is the active directory database name and where it is located?

Name : NTDS.Dit located in c:\windows\ntds\

4)What is the expansion of .Dit ? Scalable size of NTDS in 2k3?

Dit – Directory Information Tree. It is scalable up to 70 TB.

5) What is schema in AD?

The Active Directory schema defines objects that can be stored in Active Directory. The schema is a list of definitions that determines the kinds of objects and the types of information about those objects that can be stored in Active Directory. Because the schema definitions themselves are stored as objects, they can be administered in the same manner as the rest of the objects in Active Directory. Normally called schema object or metadata.

6) Structure of AD in 2kX?

1)Physical structure

Sites ,Domain Controllers

2)Logical structures

Forest, Tree, Domain, OU, object

7) What are the domain functional levels in 2k3?

1)Mixed mode

2)Native mode

3)Interim mode

8) What is Global catalog and GC server?

The global catalog is the central repository of information about objects in a tree or forest. By default, a global catalog is created automatically on the initial domain controller in the first domain in the forest. A domain controller that holds a copy of the global catalog is called a global catalog server.

9) What are the functions of GC?

A) It enables a user to log on to a network by providing universal group membership information to a domain controller when a logon process is initiated.

B) It enables finding directory information regardless of which domain in the forest actually contains the data.

10) What is the active directory database engine name?

ESE (Extensible Storage Engine)

11) What are the partitions available in AD?

i) Schema partition

ii) Configuration Partition

iii) Domain Partition

iv)Application Partition

12) What are the two types of replications?

Inter-site (Site to site) and Intra-site (With in site) replications.

13) What is KCC? What is the function of the KCC?

The KCC is a built-in process that runs on all domain controllers. The KCC configures connection objects between domain controllers. Within a site, each KCC generates its own connections. For replication between sites, a single KCC per site generates all connections between sites.

14) What is the two trust protocols 2k3 using?

Kerberos V5 and NTLM

15) What are the trust relations available in 2k3?

Tree-Root , Parent- Child , Shortcut, Realm, Forest trust , External trust

16)What is the hierarchy of applying Gpo in 2k3?

It is applied from parent level to child level in AD.

i) Local GPO

ii) GPOs linked to sites

iii) GPOs linked to domains

iv) GPOs linked to OUs

17) What are the protocols used on replication?

RPC over IP (Used for synchronies transfer) , SMTP over IP (Asynchronies transfer)

18) What is the default time delay on replication?

Intra site – 15 min ( KCC automatically create the topology for Replication)

Inter-site – 1 hrs.

Security related changes replicated immediately across sites.

19) What Different tables available in NTDS database?

i) Schema table

Ii) Link Table

iii) Data table

iv)Configuration Table

19) Where is the FRS logs stored in and what is the database engine name?

c:\windows\ntfrs\jet\log, The engine used is jet database engine. Ntfrs.jdb.

20) What is tombstone object in AD? What is its life time?

Any objects deleted from Active directory will not removed from Database immediately. That object is called tombstone object. The default life time for that object is 60 days. For win 2k3 SP1 180 days

21) FSMO Roles

In a forest, there are at least five FSMO roles that are assigned to one or more domain controllers. The five FSMO roles are

Schema Master:

The schema master domain controller controls all updates and modifications to the schema. To update the schema of a forest, you must have access to the schema master. There can be only one schema master in the whole forest.

Domain naming master

The domain naming master domain controller controls the addition or removal of domains in the forest. There can be only one domain naming master in the whole forest.

Infrastructure Master:

The infrastructure is responsible for updating references from objects in its domain to objects in other domains. At any one time, there can be only one domain controller acting as the infrastructure master in each domain.

Relative ID (RID) Master:

The RID master is responsible for processing RID pool requests from all domain controllers in a particular domain. At any one time, there can be only one domain controller acting as the RID master in the domain.

PDC Emulator

The PDC emulator is a domain controller that advertises itself as the primary domain controller (PDC) to workstations, member servers, and domain controllers that are running earlier versions of Windows.

For example, if the domain contains computers that are not running Microsoft Windows XP Professional or Microsoft Windows 2000 client software, or if it contains Microsoft Windows NT backup domain controllers, the PDC emulator master acts as a Windows NT PDC.

It is also the Domain Master Browser, and it handles password discrepancies. At any one time, there can be only one domain controller acting as the PDC emulator master in each domain in the forest

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Quicker Q&A

What are the required components of Windows Server 2003 for installing Exchange 2003? - ASP.NET, SMTP, NNTP, W3SVC

What must be done to an AD forest before Exchange can be deployed? - Setup /forestprep

What Exchange process is responsible for communication with AD? - DSACCESS

What 3 types of domain controller does Exchange access? - Normal Domain Controller, Global Catalog, Configuration Domain Controller

What connector type would you use to connect to the Internet, and what are the two methods of sending mail over that connector? - SMTP Connector: Forward to smart host or use DNS to route to each address

How would you optimise Exchange 2003 memory usage on a Windows Server 2003 server with more than 1Gb of memory? - Add /3Gb switch to boot.ini

What would a rise in remote queue length generally indicate? - This means mail is not being sent to other servers. This can be explained by outages or performance issues with the network or remote servers.

What would a rise in the Local Delivery queue generally mean? - This indicates a performance issue or outage on the local server. Reasons could be slowness in consulting AD, slowness in handing messages off to local delivery or SMTP delivery. It could also be databases being dismounted or a lack of disk space.

What are the standard port numbers for SMTP, POP3, IMAP4, RPC, LDAP and Global Catalog? - SMTP – 25, POP3 – 110, IMAP4 – 143, RPC – 135, LDAP – 389, Global Catalog - 3268

Name the process names for the following: System Attendant? – MAD.EXE, Information Store – STORE.EXE, SMTP/POP/IMAP/OWA – INETINFO.EXE

What is the maximum amount of databases that can be hosted on Exchange 2003 Enterprise? - 20 databases. 4 SGs x 5 DBs.

What are the disadvantages of circular logging? - In the event of a corrupt database, data can only be restored to the last backup.

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1. What are the Default shares in Windows Server 2003?

By default, Windows automatically creates special hidden administrative shares that administrators, programs, and services can use to manage the computer environment or network. These special shared resources are not visible in Windows Explorer or in My Computer, but you can use the Shared Folders tool in Computer Management to view them. Depending on the configuration of your computer, you may see some or all the following special shared resources listed in the Shares folder in Shared Folders:

DriveLetter$: Root partitions and volumes are shared as the drive letter name appended with the $ character. For example, drive letters C and D are shared as C$ and D$.

ADMIN$: A resource that is used during remote administration of a computer.

IPC$: A resource that shares the named pipes that you must have for communication between programs. Note that this resource cannot be deleted.

NETLOGON: A resource that is used on domain controllers.

SYSVOL: A resources that is used on domain controllers.

PRINT$: A resource that is used during the remote administration of printers.

FAX$: A shared folder on a server that is used by fax clients during fax transmission.

Note NETLOGON and SYSVOL are not hidden shares but are instead special administrative shares. Generally, Microsoft recommends that you do not modify these special shared resources. However, if you want to remove the special shared resources and prevent them from being created automatically, you can do this by editing the registry.

1. Q) Can I changed password if my machince’s connectivity to DC who holds PDC emulator role has been fails?A) No You cant the password.

Q) i have been asked if there is set of 30 harddisk configured for raid 5 if two harddisk failed what about dataA) It depends how u had configured ur RAID its only Raid5 or with with spare if its only raid 5 then in raid5 if ur 2 nos of HDD goes then ur raid is gone.

Q) How Can i Deploy the Latest Patched in Pc through G.P. wihtout having the Admin Right in Pc.A) Create a batch file and place all the patches in the Netlogon, and deploy the batch file through GP to all the pcs so the same should take affect after restarting the pc.

Q) In Raid 5,Suppose i have 5 HDD of 10-10 GB, After configuring the Raid how much space do i have for utilise.A) -1 out of the total (eg- if u r using 5 u will get only 4 because 1 goes for parity).

Q) How Can i Resolve the Svr name through NslookupA) what exactly u want to do, nslookup command will let u know through which server u r getting routed, (eg- c:\nslookup then u will get ur domain name to which u r getting routed. and if u want to get the name of the pc/server with the ip address then u have to give the command c:\nbtstat -a ip xx-xx-xx-xx)

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1. DHCP relay agent where to place it?

Ans: DHCP Relay agent u need to place in Software Router.

How many Zones in Windows 2000 server and Windows 2003 Server ?

Ans: In Windows 2000 there are mainly 3 zones

Standard Primary — zone information is written in Txt fileStandard Secondary — copy of PrimaryActive Directory Integrated– Information stores in Active Directory

In Win2k3 one more zone is added that is Stub zone

–Stub is like secondary but it contains only copy of SOA records, copy of NS records, copy of A records for that zone. No copy of MX, SRV records etc.,With this Stub zone DNS traffic will be low

Question: What is Kerberos? Which version is currently used by Windows? How does Kerberos work?

Answer: Kerberos is the user authentication used in Win2000 and Win2003 Active Directory servers

Kerberos version in 5.0

Port is: 88

It’s more secure and encrypted than NTLM (NT authentication)

1. Which protocol is used for Public Folder?

ANS: SMTP

What is the use of NNTP with exchange?

ANS: This protocol is used the news group in exchange.

1. What is the content of System State backup?

The contents are: Boot files, system filesActive directory (if it’s done on DC)SysVol folder(if it done on DC)Certificate service ( on a CA server)Cluster database ( on a cluster server)registryPerformance counter configuration informationComponent services class registration database


Q: What are the perquisites for installation of Exchange Server?

The prerequisite are

IISSMTPWWW serviceNNTP.NET FrameworkASP.NETThen run ForestprepThen run domainprep

Question: What is Multi Master Replication?

Answer: Multi-master replication is a method of replication employed by databases to transfer data or changes to data across multiple computers within a group. Multi-master replication can be contrasted with a master-slave method (also known as single-master replication).

DFS? DFS Namespace ?

1. DFS Replication. New state-based, multimaster replication engine that is optimized for WAN environments. DFS Replication supports replication scheduling, bandwidth throttling, and a new byte-level compression algorithm known as remote differential compression (RDC).

DFS Namespaces. Technology that helps administrators group shared folders located on different servers and present them to users as a virtual tree of folders known as a namespace. DFS Namespaces was formerly known as Distributed File System in Windows 2000 Server and Windows Server 2003.


What are the four domain functional levels?

Windows 2000 MixedWindows 2000 NativeWindows Server 2003 InterimWindows Server 2003

Windows 2000 Mixed


When you configure a new Windows Server 2003 domain, the default domain functional level is Windows 2000 mixed.Under this domain functional level, Windows NT, 2000, and 2003 domain controllers are supported. However,certain features such as group nesting, universal groups, and so on are not available.


Windows 2000 Native

Upgrading the functional level of a domain to Windows 2000 Native should only be done if there areno Windows NT domain controllers remaining on the network. By upgrading to Windows 2000 Native functional level,additional features become available including: group nesting, universal groups, SID History, and the ability to convertsecurity groups and distribution groups.

Windows Server 2003 Interim


The third functional level is Windows Server 2003 Interim and it is often used when upgrading from Windows NT to Windows Server 2003. Upgrading to this domain functional level provides support for Windows NT and Windows Server 2003 domain controllers. However, like Windows 2000 Mixed, it does not provide new features.


Windows Server 2003The last functional level is Windows Server 2003. This domain functional level only provides support forWindows Server 2003 domain controllers. If you want to take advantage of all the features included withWindows Server 2003, you must implement this functional level. One of the most important features introducedat this functional level is the ability to rename domain controllers

Network Interview Questions

Network Interview Questions

U What are the two types of transmission technology available?

(i) Broadcast and (ii) point-to-point

What is subnet?

A generic term for section of a large networks usually separated by a bridge or router.

Difference between the communication and transmission.

Transmission is a physical movement of information and concern issues like bit polarity, synchronization, clock etc.

Communication means the meaning full exchange of information between two communication media.

What are the possible ways of data exchange?

(i) Simplex (ii) Half-duplex (iii) Full-duplex.

What is SAP?

Series of interface points that allow other computers to communicate with the other layers of network protocol stack.

What do you meant by "triple X" in Networks?

The function of PAD (Packet Assembler Disassembler) is described in a document known as X.3. The standard protocol has been defined between the terminal and the PAD, called X.28; another standard protocol exists between hte PAD and the network, called X.29. Together, these three recommendations are often called "triple X"

What is frame relay, in which layer it comes?

Frame relay is a packet switching technology. It will operate in the data link layer.

What is terminal emulation, in which layer it comes?

Telnet is also called as terminal emulation. It belongs to application layer.

What is Beaconing?

The process that allows a network to self-repair networks problems. The stations on the network notify the other stations on the ring when they are not receiving the transmissions. Beaconing is used in Token ring and FDDI networks.

What is redirector?

Redirector is software that intercepts file or prints I/O requests and translates them into network requests. This comes under presentation layer.

What is NETBIOS and NETBEUI?

NETBIOS is a programming interface that allows I/O requests to be sent to and received from a remote computer and it hides the networking hardware from applications.

NETBEUI is NetBIOS extended user interface. A transport protocol designed by microsoft and IBM for the use on small subnets.

What is RAID?

A method for providing fault tolerance by using multiple hard disk drives.

What is passive topology?

When the computers on the network simply listen and receive the signal, they are referred to as passive because they don’t amplify the signal in any way. Example for passive topology - linear bus.

What is Brouter?

Hybrid devices that combine the features of both bridges and routers.

What is cladding?

A layer of a glass surrounding the center fiber of glass inside a fiber-optic cable.

What is point-to-point protocol

A communications protocol used to connect computers to remote networking services including Internet service providers.

How Gateway is different from Routers?

A gateway operates at the upper levels of the OSI model and translates information between two completely different network architectures or data formats

What is attenuation?

The degeneration of a signal over distance on a network cable is called attenuation.

What is MAC address?

The address for a device as it is identified at the Media Access Control (MAC) layer in the network architecture. MAC address is usually stored in ROM on the network adapter card and is unique.

Difference between bit rate and baud rate.

Bit rate is the number of bits transmitted during one second whereas baud rate refers to the number of signal units per second that are required to represent those bits.

baud rate = bit rate / N

where N is no-of-bits represented by each signal shift.

What is Bandwidth?

Every line has an upper limit and a lower limit on the frequency of signals it can carry. This limited range is called the bandwidth.

What are the types of Transmission media?

Signals are usually transmitted over some transmission media that are broadly classified in to two categories.

Guided Media:

These are those that provide a conduit from one device to another that include twisted-pair, coaxial cable and fiber-optic cable. A signal traveling along any of these media is directed and is contained by the physical limits of the medium. Twisted-pair and coaxial cable use metallic that accept and transport signals in the form of electrical current. Optical fiber is a glass or plastic cable that accepts and transports signals in the form of light.

b) Unguided Media:

This is the wireless media that transport electromagnetic waves without using a physical conductor. Signals are broadcast either through air. This is done through radio communication, satellite communication and cellular telephony.

What is Project 802?

It is a project started by IEEE to set standards to enable intercommunication between equipment from a variety of manufacturers. It is a way for specifying functions of the physical layer, the data link layer and to some extent the network layer to allow for interconnectivity of major LAN

protocols.

It consists of the following:

802.1 is an internetworking standard for compatibility of different LANs and MANs across protocols.

802.2 Logical link control (LLC) is the upper sublayer of the data link layer which is non-architecture-specific, that is remains the same for all IEEE-defined LANs.

Media access control (MAC) is the lower sublayer of the data link layer that contains some distinct modules each carrying proprietary information specific to the LAN product being used. The modules are Ethernet LAN (802.3), Token ring LAN (802.4), Token bus LAN (802.5).

802.6 is distributed queue dual bus (DQDB) designed to be used in MANs.

What is Protocol Data Unit?

The data unit in the LLC level is called the protocol data unit (PDU). The PDU contains of four fields a destination service access point (DSAP), a source service access point (SSAP), a control field and an information field. DSAP, SSAP are addresses used by the LLC to identify the protocol stacks on the receiving and sending machines that are generating and using the data. The control field specifies whether the PDU frame is a information frame (I - frame) or a supervisory frame (S - frame) or a unnumbered frame (U - frame).

What are the different type of networking / internetworking devices?

Repeater:

Also called a regenerator, it is an electronic device that operates only at physical layer. It receives the signal in the network before it becomes weak, regenerates the original bit pattern and puts the refreshed copy back in to the link.

Bridges:

These operate both in the physical and data link layers of LANs of same type. They divide a larger network in to smaller segments. They contain logic that allow them to keep the traffic for each segment separate and thus are repeaters that relay a frame only the side of the segment containing the intended recipent and control congestion.

Routers:

They relay packets among multiple interconnected networks (i.e. LANs of different type). They operate in the physical, data link and network layers. They contain software that enable them to determine which of the several possible paths is the best for a particular transmission.

Gateways:

They relay packets among networks that have different protocols (e.g. between a LAN and a WAN). They accept a packet formatted for one protocol and convert it to a packet formatted for another protocol before forwarding it. They operate in all seven layers of the OSI model.

What is ICMP?

ICMP is Internet Control Message Protocol, a network layer protocol of the TCP/IP suite used by hosts and gateways to send notification of datagram problems back to the sender. It uses the echo test / reply to test whether a destination is reachable and responding. It also handles both control and error messages.

What are the data units at different layers of the TCP / IP protocol suite?

The data unit created at the application layer is called a message, at the transport layer the data unit created is called either a segment or an user datagram, at the network layer the data unit created is called the datagram, at the data link layer the datagram is encapsulated in to a frame and finally transmitted as signals along the transmission media.

What is difference between ARP and RARP?

The address resolution protocol (ARP) is used to associate the 32 bit IP address with the 48 bit physical address, used by a host or a router to find the physical address of another host on its network by sending a ARP query packet that includes the IP address of the receiver.

The reverse address resolution protocol (RARP) allows a host to discover its Internet address when it knows only its physical address.

What is the minimum and maximum length of the header in the TCP segment and IP datagram?

The header should have a minimum length of 20 bytes and can have a maximum length of 60 bytes.

What is the range of addresses in the classes of internet addresses?

Class A 0.0.0.0 - 127.255.255.255

Class B 128.0.0.0 - 191.255.255.255

Class C 192.0.0.0 - 223.255.255.255

Class D 224.0.0.0 - 239.255.255.255

Class E 240.0.0.0 - 247.255.255.255

What is the difference between TFTP and FTP application layer protocols?

The Trivial File Transfer Protocol (TFTP) allows a local host to obtain files from a remote host but does not provide reliability or security. It uses the fundamental packet delivery services offered by UDP.

The File Transfer Protocol (FTP) is the standard mechanism provided by TCP/IP for copying a file from one host to another. It uses the services offer by TCP and so is reliable and secure. It establishes two connections (virtual circuits) between the hosts, one for data transfer and another for control information.

What are major types of networks and explain?

Server-based network

Peer-to-peer network

Peer-to-peer network, computers can act as both servers sharing resources and as clients using the resources.

Server-based networks provide centralized control of network resources and rely on server computers to provide security and network administration

What are the important topologies for networks?

BUS topology:

In this each computer is directly connected to primary network cable in a single line.

Advantages:

Inexpensive, easy to install, simple to understand, easy to extend.

STAR topology:

In this all computers are connected using a central hub.

Advantages:

Can be inexpensive, easy to install and reconfigure and easy to trouble shoot physical problems.

RING topology:

In this all computers are connected in loop.

Advantages:

All computers have equal access to network media, installation can be simple, and signal does not degrade as much as in other topologies because each computer regenerates it.

What is mesh network?

A network in which there are multiple network links between computers to provide multiple paths for data to travel.

What is difference between baseband and broadband transmission?

In a baseband transmission, the entire bandwidth of the cable is consumed by a single signal. In broadband transmission, signals are sent on multiple frequencies, allowing multiple signals to be sent simultaneously.

Explain 5-4-3 rule?

In a Ethernet network, between any two points on the network ,there can be no more than five network segments or four repeaters, and of those five segments only three of segments can be populated.

What MAU?

In token Ring, hub is called Multistation Access Unit (MAU).

What is the difference between routable and non- routable protocols?

Routable protocols can work with a router and can be used to build large networks. Non-Routable protocols are designed to work on small, local networks and cannot be used with a router

Why should you care about the OSI Reference Model?

It provides a framework for discussing network operations and design.

What is logical link control?

One of two sub layers of the data link layer of OSI reference model, as defined by the IEEE 802 standard. This sub layer is responsible for maintaining the link between computers when they are sending data across the physical network connection.

What is virtual channel?

Virtual channel is normally a connection from one source to one destination, although multicast connections are also permitted. The other name for virtual channel is virtual circuit.

What is virtual path?

Along any transmission path from a given source to a given destination, a group of virtual circuits can be grouped together into what is called path.

What is packet filter?

Packet filter is a standard router equipped with some extra functionality. The extra functionality allows every incoming or outgoing packet to be inspected. Packets meeting some criterion are forwarded normally. Those that fail the test are dropped.

What is traffic shaping?

One of the main causes of congestion is that traffic is often busy. If hosts could be made to transmit at a uniform rate, congestion would be less common. Another open loop method to help manage congestion is forcing the packet to be transmitted at a more predictable rate. This is called traffic shaping.

What is multicast routing?

Sending a message to a group is called multicasting, and its routing algorithm is called multicast routing.

What is region?

When hierarchical routing is used, the routers are divided into what we will call regions, with each router knowing all the details about how to route packets to destinations within its own region, but knowing nothing about the internal structure of other regions.

What is silly window syndrome?

It is a problem that can ruin TCP performance. This problem occurs when data are passed to the sending TCP entity in large blocks, but an interactive application on the receiving side reads 1 byte at a time.

What are Digrams and Trigrams?

The most common two letter combinations are called as digrams. e.g. th, in, er, re and an. The most common three letter combinations are called as trigrams. e.g. the, ing, and, and ion.

Expand IDEA.

IDEA stands for International Data Encryption Algorithm.

What is wide-mouth frog?

Wide-mouth frog is the simplest known key distribution center (KDC) authentication protocol.

What is Mail Gateway?

It is a system that performs a protocol translation between different electronic mail delivery protocols.

What is IGP (Interior Gateway Protocol)?

It is any routing protocol used within an autonomous system.

What is EGP (Exterior Gateway Protocol)?

It is the protocol the routers in neighboring autonomous systems use to identify the set of networks that can be reached within or via each autonomous system.

What is autonomous system?

It is a collection of routers under the control of a single administrative authority and that uses a common Interior Gateway Protocol.

What is BGP (Border Gateway Protocol)?

It is a protocol used to advertise the set of networks that can be reached with in an autonomous system. BGP enables this information to be shared with the autonomous system. This is newer than EGP (Exterior Gateway Protocol).

What is Gateway-to-Gateway protocol?

It is a protocol formerly used to exchange routing information between Internet core routers.

What is NVT (Network Virtual Terminal)?

It is a set of rules defining a very simple virtual terminal interaction. The NVT is used in the start of a Telnet session.

What is a Multi-homed Host?

It is a host that has a multiple network interfaces and that requires multiple IP addresses is called as a Multi-homed Host.

What is Kerberos?

It is an authentication service developed at the Massachusetts Institute of Technology. Kerberos uses encryption to prevent intruders from discovering passwords and gaining unauthorized access to files.

What is OSPF?

It is an Internet routing protocol that scales well, can route traffic along multiple paths, and uses knowledge of an Internet's topology to make accurate routing decisions.

What is Proxy ARP?

It is using a router to answer ARP requests. This will be done when the originating host believes that a destination is local, when in fact is lies beyond router.

What is SLIP (Serial Line Interface Protocol)?

It is a very simple protocol used for transmission of IP datagrams across a serial line.

What is RIP (Routing Information Protocol)?

It is a simple protocol used to exchange information between the routers.

What is source route?

It is a sequence of IP addresses identifying the route a datagram must follow. A source route may optionally be included in an IP datagram header.