Networking Interview Questions

Network engineer interview questions
OSPF
· Describe OSPF in your own words.
· OSPF areas, the purpose of having each of them
· Types of OSPF LSA, the purpose of each LSA type
· What exact LSA type you can see in different areas
· How OSPF establishes neighboor relation, what the stages are
· If OSPF router is stucked in each stage what the problem is and how to troubleshoot it
· OSPF hierarchy in the single or multi areas. Cool OSPF behavior in broadcast and nonbroadcast
· Draw the diagram of typical OSPF network and explain generally how it works, DR, BDR, election, ASBR, ABR, route redistribution and summarization
STP
· How it works and the purpose
· Diff types (SSTP, MSTP, RSTP) Cisco - PVST/PVST+
· root election
· Diff. port stages and timing for convergence
· Draw the typical diagram and explain how diff types of STP work
· What ports are blocking or forwarding
· How it works if there are topology changes
ACLs
· What are they
· Diff types
· Write an example if you want to allow and to deny…
· Well-known port numbers (DNS - 53 and etc…)
QOS
· What is that
· What is the diff b/w L2 and L3 QoS
· How it works
Network:
· Draw the typical network diagram you have to deal with
· explain how it works
· What part of it you are responsible
· firewall, what is that, how it works, how it is diff from ACLs
· What problems with the network you had had and how you solved it.
· What are the ways to troubleshoot the network, techniques, commands
· network security, ways to achieve it
Switching:
· VLANs
· STP
· How a L2 switch works with broadcast, unicast, multicast, known/unknown traffic
· VRRP, GLBP
· port monitoring and mirroring
· L3 switch, how it works
· PIM sparse and dense modes
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Windows admin interview questions
1. Describe how the DHCP lease is obtained. It’s a four-step process consisting of (a) IP request, (b) IP offer, © IP selection and (d) acknowledgement.
2. I can’t seem to access the Internet, don’t have any access to the corporate network and on ipconfig my address is 169.254.*.*. What happened? The 169.254.*.* netmask is assigned to Windows machines running 98/2000/XP if the DHCP server is not available. The name for the technology is APIPA (Automatic Private Internet Protocol Addressing).
3. We’ve installed a new Windows-based DHCP server, however, the users do not seem to be getting DHCP leases off of it. The server must be authorized first with the Active Directory.
4. How can you force the client to give up the dhcp lease if you have access to the client PC? ipconfig /release
5. What authentication options do Windows 2000 Servers have for remote clients? PAP, SPAP, CHAP, MS-CHAP and EAP.
6. What are the networking protocol options for the Windows clients if for some reason you do not want to use TCP/IP? NWLink (Novell), NetBEUI, AppleTalk (Apple).
7. What is data link layer in the OSI reference model responsible for? Data link layer is located above the physical layer, but below the network layer. Taking raw data bits and packaging them into frames. The network layer will be responsible for addressing the frames, while the physical layer is reponsible for retrieving and sending raw data bits.
8. What is binding order? The order by which the network protocols are used for client-server communications. The most frequently used protocols should be at the top.
9. How do cryptography-based keys ensure the validity of data transferred across the network? Each IP packet is assigned a checksum, so if the checksums do not match on both receiving and transmitting ends, the data was modified or corrupted.
10. Should we deploy IPSEC-based security or certificate-based security? They are really two different technologies. IPSec secures the TCP/IP communication and protects the integrity of the packets. Certificate-based security ensures the validity of authenticated clients and servers.
11. What is LMHOSTS file? It’s a file stored on a host machine that is used to resolve NetBIOS to specific IP addresses.
12. What’s the difference between forward lookup and reverse lookup in DNS? Forward lookup is name-to-address, the reverse lookup is address-to-name.
13. How can you recover a file encrypted using EFS? Use the domain recovery agent.
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Network engineer/architect interview questions
1. Explain how traceroute, ping, and tcpdump work and what they are used for?
2. Describe a case where you have used these tools to troubleshoot.
3. What is the last major networking problem you troubleshot and solved on your own in the last year?
4. What LAN analyzer tools are you familiar with and describe how you use them to troubleshoot and on what media and network types.
5. Explain the contents of a routing table (default route, next hop, etc.)
6. What routing protocols have you configured?
7. Describe the commands to set up a route.
8. What routing problems have you troubleshot?
9. How do you display a routing table on a Cisco? On a host?
10. How do you use a routing table and for what?
11. What is a route flap?
12. What is a metric?
13. When do you use BGP, IGRP, OSPF, Static Routes?
14. What do you see as current networking security issues (e.g. NFS mounting, spoofing, one time passwords, etc.)?
15. Describe a routing filter and what it does.
16. Describe an access list and what it does.
17. What is a network management system?
18. Describe how SNMP works.
19. Describe the working environment you are currently in, e.g. frequent interruptions, frequent priority shifting, team or individual.
20. What do you use to write documentation? Editor? Mail reader?
21. What platform (s) do you currently work on at your desk?
22. How do you manage multiple concurrent high level projects?
23. Describe a recent short term stressful situation and how you managed it.
24. How do you manage a long term demanding stressful work environment?
25. Have you worked in an assignment based environment, e.g. work request/trouble ticket system, and if so, describe that environment.
26. Describe what network statistics or measurement tools you are familiar with and how you have used them.
27. Describe what a VPN is and how it works.
28. Describe how VoIP works.
29. Describe methods of QoS.
30. How does ToS bit work?
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CCNA/Cisco admin interview questions
1. You need to retrieve a file from the file server for your word processing application, which layer of the OSI model is responsible for this function?
1. Presentation layer
2. Application layer
3. Session layer
4. Transport layer
5. Datalink layer
2. You are working in a word processing program, which is run from the file server. Your data comes back to you in an unintelligible manner. Which layer of the OSI model would you investigate?
1. Application layer
2. Presentation layer
3. Session layer
4. Network layer
5. Datalink layer
3. The IEEE subdivided the datalink layer to provide for environments that need connectionless or connection-oriented services. What are the two layers called?
1. Physical
2. MAC
3. LLC
4. Session
5. IP
4. You are working with graphic translations. Which layer of the OSI model is responsible for code formatting and conversion and graphic standards.
1. Network layer
2. Session layer
3. Transport layer
4. Presentation layer
5. Which is the best definition of encapsulation?
1. Each layer of the OSI model uses encryption to put the PDU from the upper layer into its data field. It adds header and trailer information that is available to its counterpart on the system that will receive it.
2. Data always needs to be tunneled to its destination so encapsulation must be used.
3. Each layer of the OSI model uses compression to put the PDU from the upper layer into its data field. It adds header and trailer information that is available to its counterpart on the system that will receive it.
4. Each layer of the OSI model uses encapsulation to put the PDU from the upper layer into its data field. It adds header and trailer information that is available to its counterpart on the system that will receive it.
6. Routers can be configured using several sources. Select which of the following sources can be used.
1. Console Port
2. Virtual Terminals
3. TFTP Server
4. Floppy disk
5. Removable media
7. Which memory component on a Cisco router contains the dynamic system configuration?
1. ROM
2. NVRAM
3. Flash
4. RAM/DRAM
8. Which combination of keys will allow you to view the previous commands that you typed at the router?
1. ESC-P
2. Ctrl-P
3. Shift-P
4. Alt-P
9. Which commands will display the active configuration parameters?
1. show running-config
2. write term
3. show version
4. display term
10. You are configuring a router, which prompt tells you that you are in the privileged EXEC mode?
1. @
2. >
3. !
4. :
5. #
11. What does the command “IP name-server 255.255.255.255″ accomplish?
1. It disables domain name lookup.
2. It sets the domain name lookup to be a local broadcast.
3. This is an illegal command.
4. The command is now defunct and has been replaced by “IP server-name ip any”
12. The following selections show the command prompt and the configuration of the IP network mask. Which two are correct?
1. Router(config-if)#netmask-format { bitcount decimal hexadecimal }
2. Router#term IP netmask-format { bitcount decimal hexadecimal }
3. Router(config-if)#IP netmask-format { bitcount decimal hexadecimal }
4. Router#ip netmask-format { bitcount decimal hexadecimal }
13. Which layer is responsible for flow control with sliding windows and reliability with sequence numbers and acknowledgments?
1. Transport
2. Application
3. Internet
4. Network Interface
14. Which processes does TCP, but not UDP, use?
1. Windowing
2. Acknowledgements
3. Source Port
4. Destination Port
15. Select which protocols use distance vector routing?
1. OSPF
2. RIP
3. IGRP
4. PPP
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Networking and Unix interview questions
What is UTP?
UTP — Unshielded twisted pair 10BASE-T is the preferred Ethernet medium of the 90s. It is based on a star topology and provides a number of advantages over coaxial media:
It uses inexpensive, readily available copper phone wire. UTP wire is much easier to install and debug than coax. UTP uses RG-45 connectors, which are cheap and reliable.
What is a router? What is a gateway?
Routers are machines that direct a packet through the maze of networks that stand between its source and destination. Normally a router is used for internal networks while a gateway acts a door for the packet to reach the ‘outside’ of the internal network
What is Semaphore? What is deadlock?
Semaphore is a synchronization tool to solve critical-section problem, can be used to control access to the critical section for a process or thread. The main disadvantage (same of mutual-exclusion) is require busy waiting. It will create problems in a multiprogramming system, where a single CPU is shared among many processes.
Busy waiting wastes CPU cycles.
Deadlock is a situation when two or more processes are waiting indefinitely for an event that can be caused by only one of the waiting processes. The implementation of a semaphore with a waiting queue may result in this situation.
What is Virtual Memory?
Virtual memory is a technique that allows the execution of processes that may not be completely in memory. A separation of user logical memory from physical memory allows an extremely large virtual memory to be provided for programmers when only a smaller physical memory is available. It is commonly implemented by demand paging. A demand paging system is similar to a paging system with swapping. Processes reside on secondary memory (which is usually a disk). When we want to execute a process, we swap it into memory.
Explain the layered aspect of a UNIX system. What are the layers? What does it mean to say they are layers?
A UNIX system has essentially three main layers:
. The hardware
. The operating system kernel
. The user-level programs
The kernel hides the system’s hardware underneath an abstract, high-level programming interface. It is responsible for implementing many of the facilities that users and user-level programs take for granted.
The kernel assembles all of the following UNIX concepts from lower-level hardware features:
. Processes (time-sharing, protected address space)
. Signals and semaphores
. Virtual Memory (swapping, paging, and mapping)
. The filesystem (files, directories, namespace)
. Pipes and network connections (inter-process communication)
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.
These questions were sent in from IBM. They discuss various telecom and networking topics.
OSPF
Describe OSPF in your own words.
OSPF areas, the purpose of having each of them
Types of OSPF LSA, the purpose of each LSA type
What exact LSA type you can see in different areas
How OSPF establishes neighboor relation, what the stages are
If OSPF router is stucked in each stage what the problem is and how to troubleshoot it
OSPF hierarchy in the single or multi areas. Cool OSPF behavior in broadcast and nonbroadcast
Draw the diagram of typical OSPF network and explain generally how it works, DR, BDR, election, ASBR, ABR, route redistribution and summarization
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Posted in: Networking Comments(0)
More than 200 CCNA questions
As system administrator, you type “debug ipx sap” and receive the following lines as part of the IOS response: type 0×4, “HELLO2″, 199.0002.0003.0006 (451), 2 hops type 0×4, “HELLO1″, 199.0002.0003.0008 (451), 2 hops What does “0×4″ signify?* That is a Get Nearest Server response.* That it is a General query.* That it is a General response.* That it is a Get Nearest Server request.Correct answer: A
To monitor IP igrp traffic, you can use “debug IP igrp transaction” or “debug IP igrp events”. How do you display information about IPX routing update packets?* debug routing* debug ipx transaction* debug ipx routing activity* debug ipx eventsCorrect answer: C
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Posted in: Networking Comments(7)
Networking questions
What is a default gateway? - The exit-point from one network and entry-way into another network, often the router of the network.
How do you set a default route on an IOS Cisco router? - ip route 0.0.0.0 0.0.0.0 x.x.x.x [where x.x.x.x represents the destination address]
What is the difference between a domain local group and a global group? - Domain local groups grant permissions to objects within the domain in which the reside. Global groups contain grant permissions tree or forest wide for any objects within the Active Directory.
What is LDAP used for? - LDAP is a set of protocol used for providing access to information directories.
What tool have you used to create and analyze packet captures? - Network Monitor in Win2K / Win2K3, Ethereal in Linux, OptiView Series II (by Fluke Networks).
How does HSRP work?
What is the significance of the IP address 255.255.255.255? - The limited broadcast address is utilized when an IP node must perform a one-to-everyone delivery on the local network but the network ID is unknown.
What is Active Directory schema?
What are the domain functional level in Windows Server 2003?
What are the forest functional level in Windows Server 2003?
What is global catalog server?
How we can raise domain functional & forest functional level in Windows Server 2003?
Which is the deafult protocol used in directory services?
What is IPv6?
What is the default domain functional level in Windows Server 2003?
What are the physical & logical components of ADS
In which domain functional level, we can rename domain name?
What is multimaster replication?
What is a site?
Which is the command used to remove active directory from a domain controler?
How we can create console, which contain schema?
What is trust?
What is the file that’s responsible for keep all Active Directory database?
Posted in: Networking, Windows
51 Responses to “Windows sysadmin interview questions”
Aneesh Says: March 29th, 2006 at 11:49 pm
The Active Directory schema contains formal definitions of every object class that can be created in an Active Directory forest it also contains formal definitions of every attribute that can exist in an Active Directory object.Active Directory stores and retrieves information from a wide variety of applications and services. So that it can store and replicate data from a potentially infinite variety of sources, Active Directory standardizes how data is stored in the directory. By standardizing how data is stored, the directory service can retrieve, update, and replicate data while ensuring that the integrity of the data is maintained.
kiran Says: May 15th, 2006 at 11:46 pm
1) Schema master is a set of rules which is used to define the struture of active directory. It contains definitions of all the objects which are stored in AD. It maintains information and detail information of objects.
2) If there are many organisational units and to implement policy on all OUś we use Domain level policy.
3)
4) Global Catalog Server maintains full information about its own domain and partial information about other domains. It is a forest wide role.
12) Sites: one or more well-connected highly reliable and fast TCP/IP subnets. A site allows administrator to configure active directory access and replication topology to take advantage of the physical network.
13) dcpromo to add/remove active directory but first ADC should be removed before DC if we want to remove DC first then check this server is last domain controller in domain.
16) I think the answer for this is schema master.
Pinkesh Says: June 3rd, 2006 at 8:00 am
Can you explain us briefly Archeitecture of Windows 2000/2003?
Pinkesh Says: June 3rd, 2006 at 8:01 am
What are main differences in Windows NT and Windows 2000 Archeitecture ?
Muniraj Says: June 24th, 2006 at 2:41 am
HII was just googling for Interview FAQ’s i got this URL as first choiceit is really dream come true situation for me because readily all possible question’s and answers are given.
Please send me if u have any FAQ on Exchnage Related.
Thanx and regardsMuniraj
shaik Says: June 29th, 2006 at 2:31 am
HII was just googling for Interview FAQ’s i got this URL as first choiceit is really dream come true situation for me because readily all possible question’s and answers are given.
Please send me if u have any FAQ on Exchnage Related.
Thanx and regards
shaik
SUVENDU Says: August 15th, 2006 at 11:08 pm
4.What is global catalog server?
A global catalog server is a domain controller it is a master searchable database that contains information about every object in everydomain in a forest. The global catalog contains a complete replica of allobjects in Active Directory for its host domain, and contains a partial replicaof all objects in Active Directory for every other domain in the forest.It have two important functions:i)Provides group membership information during logon and authenticationii)Helps users locate resources in Active Directory
SUVENDU Says: August 15th, 2006 at 11:08 pm
4.What is global catalog server?
A global catalog server is a domain controller it is a master searchable database that contains information about every object in everydomain in a forest. The global catalog contains a complete replica of allobjects in Active Directory for its host domain, and contains a partial replicaof all objects in Active Directory for every other domain in the forest.It have two important functions:i)Provides group membership information during logon and authenticationii)Helps users locate resources in Active Directory
SUVENDU Says: August 15th, 2006 at 11:11 pm
13 Which is the command used to remove active directory from a domain controler?
ANS ” DCPROMO ” in command prompt
SUVENDU Says: August 15th, 2006 at 11:29 pm
10. In which domain functional level, we can rename domain name?
All domain controllers must be running Windows Server 2003, and the Active Directory functional level must be at the Windows Server 2003.Yes u can rename the domain in windows server 2003
irfan Says: September 1st, 2006 at 1:19 am
User(s) are complaining of delays when using the network. What would you do?
shaik Says: September 3rd, 2006 at 12:24 pm
hi
15.NTDS.DIT14. we have to open the register to see the schema master fsmo roleregser 32 schmamgmt.9.Physical computers,sites,dcLogical user,o.us, etc….6.Light wait directory Access Protocal (ldap)5. What ever changes done in D.c(domain Controlers) will effect at A.Dwe can call it as multimaster .
Kumar Ken Says: September 13th, 2006 at 3:53 pm
Hi15. To allow users in one domain to access resources in another, AD uses trust. Trust is automatically produced when domains are created. The forest sets the default boundaries of trust, not the domain, and implicit trust is automatic. As well as two-way transitive trust, AD trusts can be shortcut (joins two domains in different trees, transitive, one- or two-way), forest (transitive, one- or two-way), realm (transitive or nontransitive, one- or two-way), or external (nontransitive, one- or two-way) in order to connect to other forests or non-AD domains. AD uses the Kerberos V5 protocol, although NTLM is also supported and web clients use SSL/TLS.
11.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).
7.Internet Protocol version 6 (IPv6) is a network layer IP standard used by electronic devices to exchange data across a packet-switched internetwork. It follows IPv4 as the second version of the Internet Protocol to be formally adopted for general use.
hongsinh Says: September 19th, 2006 at 3:00 am
What are the domain functional level in Windows Server 2003?
Sarith Says: September 22nd, 2006 at 3:26 am
Please check this link :) this will help youh**p://technet2.microsoft.com/WindowsServer/en/library/b3674c9b-fab9-4c1e-a8f6-7871264712711033.mspx?mfr=true
Naresh Nimmagadda Says: October 13th, 2006 at 9:06 am
ip v6it ia a 128 bit size addresshere we can see total 8 ocatates each octate size is 16 bits superated with “:”it is in hexa decimal formatethese 3 types1.unicast address2.multicast address3.anycast addressloopback address of ip v6 is ::1
Ramanand Says: November 27th, 2006 at 5:00 am
What is mean by dns,dhcp.?what is maen different between hub and switch ?what is meam by brodcast id?what is mean by loop back id?what is mean by schema ?what is mean by master searchable directory
Srikanth Says: December 8th, 2006 at 6:08 am
10. In which domain functional level, we can rename domain name?
The System Properties dialog box can also be used to rename a domain controller, and it does not require the functional level to be raised to Windows Server 2003.
Renga Raju Says: December 13th, 2006 at 11:43 pm
1.What is Rsop ?Resultant set of policy is provid to make policy modification and trouble shooting easier. Rsop is the query object it has two mode 1.logging mode: Polls existing policies and the reports the result of the query. 2.Planning mode: The questins ask about the planned policy and the report the result of the quer.2.What is the concept for authoritative and nonauthoritative restoration?1. Non-authoriative restore: which accept the entries from other domain controller after the restoed data.2.Authoritative: Not accept the entries from other domain controller.3.What is the ntds.tit file default size?40 mb
niraj Says: December 14th, 2006 at 5:28 am
13 Which is the command used to remove active directory from a domain controler?
ANS i think ” DCPROMO ” in command prompt .
11.What is multimaster replication?Ans. It is also known as single-master replication.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.
Sachin Says: February 19th, 2007 at 6:54 am
What is Multimaster replication?
In addition to storing primary zone information in Dns we can also store it in active directory as active directory object.This integrates Dns with active directory in order to take advantage of active directory features
The benefits are1 zone can be modified from any domain controller within the domain and this information is automatically updated or replicated to all the other domain controllers along with the active directory replication.This replication is said to be multimaster replication.2.We no longer face the standard dns server drawbacks.
In standard dns server only the primary server can modify the zone and then replicate the changes to other domain controllers(It was in windows NT4 before).But when Dns gets integrated with AD .Zone can be modified and replicated from any domain controller.
3.Fault tolerance4.Security
You can prevent access to any updates to zone or individual record preventing insecure dynamic updates.
Unnikrishnan Says: February 24th, 2007 at 7:08 am
13 Which is the command used to remove active directory from a domain controler?
ANS : DCPROMO
Unnikrishnan Says: February 24th, 2007 at 7:10 am
11 What is multimaster replication?
The two technologies in DFS are as follows:
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.
pavan Says: February 28th, 2007 at 2:39 pm
hi1)What is system boot process in windows and linux.2)how the hardware interact with OS.3)what is paging.
Thanks
Salman MW Says: March 7th, 2007 at 3:56 pm
8. The default domain functional level in Windows Server 2003 is “Windows 2000 Mixed”
10. We can rename domain name in “Windows Server 2003″ functional level
William Wood Says: March 13th, 2007 at 4:59 am
16. NTDS.dit
jagjit singh Says: March 26th, 2007 at 11:16 am
for removing active directory the command line is
dcpromo /forceremoval
Sanjay Patel Says: March 30th, 2007 at 1:24 pm
Removing Active Directory:1. If we want to remove Active Directory then we willuse command……DCPROMO2. If some one deleted parent domain and we want toremove from child domain then we will use command…DCPROMO /FORCEREMOVALNote: - we should not remove parent domain first. weshould start from bottom means child domainand after that it’s parent and so on.
Sanjay Patel Says: March 30th, 2007 at 1:53 pm
1. DNS(Domain Name Service):—————————-It’s mainly used to resolve from host name(FQDN-Fully Qualified Domain Name) to IP address and IP address to host name.DNS mainly used in Internet. DNS devide in form of hierarchical.
2. DHCP(Dynamic Host Configuration Protocol):———————————————DHCP use for provide IP address dnamically to client machine. If that client not able to find DHCP server then client machine will go for APIPA(We have range for APIPA which is 169.254.0.1-169.254.255.254).
3. HUB and SWITCH:——————Switch is expencive than hub. If more then one user try to send packet at a time collision will occure but in switch we can send. Switch is full duplex. Maximum bandwidth is 100 Mhz and that bandwidth is shared by all of the PC’s connected to the hub. Data can be sent in both directions simultaneously, the maximum available bandwidth is 200 Mbps, 100 Mbps each way, and there are no other PC’s with which the bandwidth must be shared.
Sanjay Patel Says: March 30th, 2007 at 1:55 pm
3. HUB and SWITCH:——————Switch is expencive than hub. If more then one user try to send packet at a time collision will occure but in switch we can send. Switch is full duplex. In hub Maximum bandwidth is 100 Mhz and that bandwidth is shared by all of the PC’s connected to the hub. In switch data can be sent in both directions simultaneously, the maximum available bandwidth is 200 Mbps, 100 Mbps each way, and there are no other PC’s with which the bandwidth must be shared.
Zahed Says: March 30th, 2007 at 2:11 pm
Hi,1.What is differnece between router and routing?2.What is dynamic routing and Static routing?
Sanjay Patel Says: March 31st, 2007 at 12:50 pm
1. Difference between Router and Routing: -——————————————-Router: -———Router is a device which is used to connect different network. A device or setup that finds the best route between any two networks, even if there are several networks to traverse. Like bridges, remote sites can be connected using routers over dedicated or switched lines to create WANs.Routing: -———-Process of delivering a message across one or more networks via the most appropriate path.
2. Dynamic Routing and Static Routing: -—————————————-Dynamic routing performs the same function as static routing except it is more robust. Static routing allows routing tables in specific routers to be set up in a static manner so network routes for packets are set. If a router on the route goes down the destination may become unreachable. Dynamic routing allows routing tables in routers to change as the possible routes change. There are several protocols used to support dynamic routing including RIP and OSPF
william wood Says: April 9th, 2007 at 5:32 am
The schema is the component of the Active Directory directory service that defines all the objects and attributes that the directory service uses to store data. You can combine some objects in the schema to create more-complex definitions if objects of greater complexity are required. You can also add new definitions to the schema to support new types of objects in the directory.
Zahed Says: April 18th, 2007 at 1:45 pm
Hi, i want to know to total process to migrate from Windows NT server to Windows 2000 server.
What are all the process will done when we start server tell me briefly which file work for which process.
Thnaks warm Regards,Zahed.
om Says: April 30th, 2007 at 11:12 am
The schema is the component of the Active Directory directory service that defines all the objects and attributes that the directory service uses to store data. You can combine some objects in the schema to create more-complex definitions if objects of greater complexity are required. You can also add new definitions to the schema to support new types of objects in the directory.
omraj Says: April 30th, 2007 at 11:13 am
Dynamic routing performs the same function as static routing except it is more robust. Static routing allows routing tables in specific routers to be set up in a static manner so network routes for packets are set. If a router on the route goes down the destination may become unreachable. Dynamic routing allows routing tables in routers to change as the possible routes change. There are several protocols used to support dynamic routing including RIP and OSPF
vijay Says: May 25th, 2007 at 7:22 am
The four domain functional levels are:
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 NativeUpgrading 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, SIDHistory, and the ability to convertsecurity groups and distribution groups.
Windows Server 2003 InterimThe third functional level is Windows Server 2003 Interim and it is often used when upgrading fromWindows NT to Windows Server 2003. Upgrading to this domain functional level provides support forWindows 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
Annveer N. Halkood Says: July 29th, 2007 at 10:58 pm
what are the types of name resolution?
how name resolution will take place?
what are the Groups?
what is DHCP Relay agent?
Thyagu Says: September 18th, 2007 at 7:48 pm
1.Active Directory schema is collection of object class and attributes.Eg user is an object and its having alot attributes such as first name ,last name etc…It present in only one domain in a forest,schema master is having the ability to update the changes in the Active directory schema.Schema Administrator only can access and edit the schema.
you cannot see the AD schema when you installed AD (dcpromo).
You need to run the registry file for schema in cmd mode :regsvr32.dll schmmgmt
Then you can see the Add -snap in wizard in mmc console ,there you can..
2.the domain functional level in Windows Server 2003
Domain fuctional level support only the windows domain controllers not client level o/s.
They are four:windows 2000 mixed(by default) supports- win nt,win 2000,win2003.Windows 2000 native- supports- win 2000 ,win 2003Windows 2003 interim- supports ->win NT,win 2003Windows 2003 - supports-win 2003 only
3.forest functional level in Windows Server 2003There are threewindows 2000 mixed supports- win nt,win 2000,win2003.Windows 2000 native- supports- win 2000 ,win 2003Windows 2003 - supports-win 2003 only
4.Global CatalogIt is a searchable database Enginee.It is used to search the objects in a forest.In 2003 ,Universal Group caching membership is available for speedy logon across domain. Port no:3268,3269It is also taking part of AD replication.
Sorry guys ,going out now… i wll cont…later
Thyagu Says: September 19th, 2007 at 5:04 pm
5.How we can raise domain functional & forest functional level in Windows Server 2003?
AD users and computers–>domain functional level->choose DFL as per your environment.
AD Domain and Trust–>Forest functional level–>choose FFL as would your environment.
Note:once you have change the DFL and FFL,cannot be revert.
6.the deafult protocol used in directory services?LDAP.
8.Already answered
9.What are the physical & logical components of ADS
Physical->sites,domain controller
Logical ->Forest,domain,tree,ou
10.In which domain functional level, we can rename domain name
Windows 2003 dfl,you can rename the domain.
Note:Not recommended to rename the domain by Microsoft itself.You need to follow up the proper procedure to prevent the further issue.Renaming is simple,but forecast issue is lot.
11.multi-master replication
Whenever a change occurs to any object within an Active Directory domain, that change is replicated automatically to all domain controllers within the domain. This process is called multi-master replication. Multi-master replication does not happen instantly across all servers simultaneously. Rather, it is a controlled process where each domain controller peer is updated and validated in a logically controlled procedure.
12.Site:
Site is one or more IP subnets.It contains connection objects and computer objects and mainly used for AD replication.
13.Dcpromo, the command used to remove active directory from a domain controler
14.Already answered.
15.Trust is relationship,between forest,domain.
16 NTDS.dit is the file that’s responsible for keep all Active Directory database.
I have answered almost question.please let me if my answer is wrong.
PREM Says: September 26th, 2007 at 7:12 am
The schema is the component of the Active Directory directory service that defines all the objects and attributes that the directory service uses to store data. You can combine some objects in the schema to create more-complex definitions if objects of greater complexity are required. You can also add new definitions to the schema to support new types of objects in the directory.
MAK Says: October 10th, 2007 at 3:01 pm
What is a default forest functionl level when you install the root domain controller ?
Raj Narayan Says: October 23rd, 2007 at 9:24 am
Hi,Can you pleas answer my query1.How to Export the Ad data in Excel.Specially Tabs Like (General,Account,Exchange Advance,Security,Members of )Without any 3rd party software.
2. Suppose i have deleted any object from Ad but after 2-3 days i want back that object..What is the process to restore the deleted Ad object.
Raj Narayan Says: November 22nd, 2007 at 4:55 am
Hi,Can anyone give me the answer of the mention Questions:1. Windows server 2008 is actual which version of Windows server ?2. Explain NAP in Windows Server 20083. How 1 can implement IP verison 6 using Windows Server 2008?4. What are the enhancements in Terminal server which comes with Win2k8 ?5. Which version of IIS comes with Windows server 2008?6. What is the new feature included in Windows Server 2008 which can lock entire hard disk drive?7. How easy it is to combine Windows Server 2008 os with physical networking & security appliances?8. What are the certifications available for Windows 2008 track?9. What is MCP member site and whats advantage of it ?10. What is TechNet subscription and what indivisual get by subscribing to TechNet?
Regards,Raj Narayan
Murali Chowdary Says: January 25th, 2008 at 8:36 am
A global catalog server is a domain controller it is a master searchable database that contains information about every object in everydomain in a forest. The global catalog contains a complete replica of allobjects in Active Directory for its host domain, and contains a partial replicaof all objects in Active Directory for every other domain in the forest.
Prasath Jayabal Says: March 3rd, 2008 at 5:34 am
What is DHCP relay agent?
If you have two or more subnet,you need to configure more DHCP server in each subnet instead of place DHCP server ,we can configure DHCP relay angent wherever you want.
Note:Minimum one DHCP server on your network
Prasath Jayabal Says: March 3rd, 2008 at 5:42 am
What is mean by dns,dhcp ?
DNS : it is Domain name system ,this is used to reslove the IP address to site name and, site name to IP address
DHCP: It is dynamic host configuration protocol,It is using to distribute the IP to all client systems in a network.
Prasath Jayabal Says: March 3rd, 2008 at 5:52 am
what is maen different between hub and switch ?
Hub :It is place of convergence where data arrives from one system ,it will forward the message to all ,it is a layer one device.
It comes under physical layer
Switch : It is place of convergence where data arrives from one system first i will see the source MAC (Media Access Contol) and destination MAC and it will forward to Particular destination MAC ID.
It is layer two device(Data Link Layer)
Prasath Jayabal Says: March 3rd, 2008 at 6:12 am
what is meam by brodcast id?It will forward the message to all system in a network (255.255.255.255).
Example : This is my Ip address 192.168.1.1/30let we find out the subnet,host address,broadcast address ?
Subnet will be 255.255.255.252My valued host address is 192.168.1.5 to 192.168.1.6My broadcast address will 192.168.1.7
Prasath Jayabal Says: March 3rd, 2008 at 6:20 am
what is mean by loop back id?
It is local host address using this we can check the TCP/IP protocol stack ,special to check the network card (127.0.0.1).
Prasath Jayabal Says: March 3rd, 2008 at 6:24 am
what is mean by schema ?
Windows Server 2000/2003 Active Directory uses a database set of rules is called Schema
Responses to “Network developer interview questions”
mala Says: October 27th, 2005 at 4:34 am
What is TCP window sizing
rrovegno Says: November 16th, 2005 at 12:10 am
1. How does TCP handshake work? Transmission Control Protocol/Internet Protocol. There are 3 steps.1. Local device sends sequence number and maximum segment size.2. Destination device responds by sending its sequence number and maximum segment size back to local device.3. Local device acknowledges receipt of the sequence number and segment size information.
2. How does SSL handshake work? Secure Sockets Layer. There are 4 steps.1. Browser checks the certificate to make sure that the site you are connecting to is the real site and not someone intercepting.2. Determine encryption types that the browser and web site server can both use to understand each other.3. Browser and Server send each other unique codes to use when scrambling (or encrypting) the information that will be sent.4. The browser and Server start talking using the encryption, the web browser shows the encrypting icon, and web pages are processed secured.
3. What is the difference between passive FTP and active FTP?FTP is an unusual protocol in that it uses two ports, one for commands and the other for data. (This is one of the reasons it is superior to HTTP for transferring large files.) Active FTP was invented first. The client initiates a connection on the server’s command port. The server then initiates a connection with the client from its data port. In Passive FTP, the client initiates both connections with the server, which remains “passive”.Active FTP may cause problems if your client is behind a firewall. From the firewall’s point of view, the FTP server that is trying to initiate a connection with your client looks like an intruder and is usually blocked. This is why many users have difficulty using FTP to download files from behind a firewall.Passive FTP solves this problem, but creates other problems, notably where FTP server security is concerned. The server must listen on a large number of ports. This requires the firewall to let a lot of unqualified traffic through. Most firewall administrators do not like this.As a rule, you do not need to be concerned about passive and active FTP unless you administer an FTP server or a firewall. If you experience difficulty using your FTP client from behind a firewall, this is likely the reason. Perhaps you should discuss the matter with your firewall administrator.
4. What is the difference between socket and session?1. An SSL session is a mechanism through which connections can be established by re-using previously negotiated handshakes.2. A socket is one endpoint of a two-way communication link between two programs running on the network. A socket is bound to a port number so that the TCP layer can identify the application that data is destined to be sent.
5. How does network management station work? Network management stations execute management applications which monitor and control network elements. Network elements are devices such as hosts, gateways, terminal servers, and the like, which have management agents responsible for performing the network management functions requested by the network management stations. The Simple Network Management Protocol (SNMP is used to communicate management information between the network management stations and the agents in the network elements. There are a few network management features that may be used to provide network monitoring for this advisory.1. Device Availability Monitoring2. SNMP MIB object monitoring3. Cisco Service Assurance Agent (Cisco SAA)4. RMON Alarm and Events5. Event-MIB6. CiscoWorks RME Network Show Commands and CLI scripting
6. What are the different phases in VPN establishment? Successful VPN establishment consists of two levels of SA’s known as phases. Phase 1 authentication establishes session keys. Using the Xauth feature, the client waits for a “username/password” challenge after the IKE Phase 1 SA has been established. When the end user responds to the challenge, the response is forwarded to the IPsec peers for an additional level of authentication completing Phase 2.1. Phase 1 of a 2 phase VPN tunnel establishment process. Phase 1 negotiates the security parameter agreement.2. Phase 2 of 2 phase VPN tunnel establishment process. Phase 2 uses the agreed parameters from Phase 1 to bring the tunnel up.
7. How does DH (deffie helman) work? Diffie-Hellman key agreement was invented in 1976 during a collaboration between Whitfield Diffie and Martin Hellman and was the first practical method for establishing a shared secret over an unprotected communications channel. Based on Ralph Merkle’s public key cryptosystem. Public key cryptography is a form of cryptography which generally allows users to communicate securely without having prior access to a shared secret key, by using a pair of cryptographic keys, designated as public key and private key, which are related mathematically.
8. What is TCP window sizing? The window size is the maximum number of bytes of data that can be transmitted in one segment. Increasing the window size for a TCP-based file transfer would increase throughput until the slowest link in the path saturates. It would be preferable to have a window size appropriate to the size of the link. There would be less buffering, the ACKs would return more quickly and more of the bandwidth would be used. Ideally you are looking for a Window Size >= Bandwidth * RTT.
9. What is MTU? Maximum Transmission Unit. The greatest amount of data or “packet” size that can be transferred in one physical frame on a network. This packet also contains the header and trailer information, which are like addresses for each packet that are required by the routers on the network.
harikrishna Says: June 19th, 2006 at 2:37 am
i have doughts in snmp1)what is mib,where they used2)whai oids why they used
Gilli Says: May 7th, 2007 at 6:38 am
Hari,
To answer your queries.
1. What is MIB..MIB is Management Information Base - just a database which contains the information of all the managed objects of the particular device.
2. What is OID ….A MIB contains many object what are know as OID (Object Identifier) to identify that particular object.
eg: RFC1213-MIB have many objects which gives you the basic information of the device, like system name, system location etc.. sysName, sysLocation are all known as OID.
karthikeyan.m(TETCOS) Says: May 23rd, 2007 at 10:47 pm
What is the difference betwenn Reno and new Reno algorithm in TCP?
Desi Dimova Says: October 19th, 2007 at 8:03 am
1. How does TCP handshake work? It’s a 3 way handshake. The client sends a SYN packet to the server. The server replies with a SYN packet and acknowledges the client’s SYN packet by sending an ACK packet. The client acknowledges the SYN packet sent by the server. SYN-SYN/ACK-SYN.2. How does SSL handshake work? The SSL handshake protocol helps determine the session key, a symmetrical key used to encrypt data after a connection has been established. The protocol sends browser’s SSL version number, encryption settings, and other crypto information to the remote host. The remote host sends back its own SSL number and cipher settings back to the client. The server may verify the client’s certificate. The client verifies the server’s CA to make sure the server is authentic. The client creates a premaster secret, a SSL session encrypted using the server’s public key and sent to the server. When the server receives the encrypted premaster secret, the server uses it to verify the client’s identity optionally. Then the premaster secret is decrypted and used to determine the session key.3. What is the difference between passive FTP and active FTP?With active FTP, a client connects to server’s command port 21 from any port n > 1023. Server responds from port 21 to client’s control port. The server initiates a connection from the server data port 20 to the client’s data port n+1. Client sends ACK to the server’s data port. In passive mode, both connections are initiated by the client. The client opens 2 random ports locally, n>1023 and n+1, sending PASV to the server’s command port 21. The server opens port m >1023 and then the client initiates the connection from port N+1 to the server’s data port m.
One Response to “Some PC and networking questions”
rrovegno Says: November 16th, 2005 at 12:07 am
1. Workers can not print from the printer, there user logon are correct and are allowed to print from that printer in active directory. How would you resolve this issue?This is vague and could have multiple responses. Here are a few.1. Verify printer is set as default.2. Verify users have local privileges set properly to print.3. Is print server delivering correct drivers?4. Is local naming convention for printer correct?5. If pre Win2000 workstation, naming convention must be less than 12 characters.6. Make sure no viruses present. Some Viruses can shut down IPC shares and printing services.
2. What is the difference between hub and switch?A hub is not smart and allows all connected nodes/networks to communicate with each other. You a are limited to 10/100Mb half duplex operation on a hub. To hook two hubs togethor you would use a crossover cable. Most hubs also have a crossover port which will allow you to use a regular cable to hook two hubs/switches togethor.A switch on the other hand can be an OSI Model layer 2 or 3 device. A switch forwards information by mac address. The mack address is a hard coded alpha numeric number that is used to identify a network adapter. Whenever a call is made to another computer, the switch looks in it’s mac address table and see’s if this node is directly connected to the switch by looking it up in the mac address database. If it is not, however, if forwards it down all switch ports looking for the destination. A layer 2 switch is even smarter. It can actually route traffic based on it’s layer 3 address. It will look up the destination in it’s mac address table first, if does not find it, it will forward it by looking at the route table and send it on it’s merry way to it’s destination. A switch will also allow you to set a switch port at 10/100Mb full duplex to increase node communication speed.Hubs should be used in smaller networking environments and switches should be used whenever you need to segment your network or you are having problems with collisions on your ethernet network. If you have over a 100 clients in a location, it’s a good idea to uses switches.If you intend on using them both, you would normally use the switch as the backbone and the hubs as connections. Each hub would have it’s own switch port on the switch. I normally reccommend that if your going to use a switch in place of a hub then get rid of all your hubs and move completely to switches. This will allow for increased network performance, a more structured segmenting of the network, and better traffic control. Hubs, since they are not smart, send broadcasts down all ports unlike a switch, which can cause performance degradation on the network. This causes all clients/nodes to have to respond to the broadcast.
3. Your hard drive is partitioned as follows: 8 gigs for OS drive C, 8 gigs for Hot Swappable drive D and rest is free as drive E. Your drive C crashes, how would you reboot your system without installing a new operating system?This is also vague and poorly put together. It is represented as a single HDD but the reference to Hot Swappable would infer a secondary device. Perhaps he misunderstands the technology. As it is unclear, this could have multiple responses as well. Here are a few.1. It is hard to tell how many physical disks there are based on the description? If it is hardware related and the first drive has literally crashed physically (head crash for example) the second drive may have an OS. As it is the only drive referred to as Hot Swappable, you may be able to remove the drive that crashed and change jumper settings on the second drive making it the primary drive. Then it will reboot provided it has an OS.2. If this is a single drive with an NT OS and it is setup with multiple boot partitions, you may be able to boot to one of the other partitions.3. You may be able to use the original OS CD or floppy disk and repair the OS installation. This is provided the HDD is ok and the partition is the only problem.4. If Hot Swappable means a secondary physical drive, where the first partition is mirrored, then down the computer and swap the drives. Re-power up.4. Your computer gives you “non-disk error” before you log on what would you do to make your computer work?Again there are potentially multiple scenarios here.1. Make sure a non OS floppy is not present in A:2. Make sure hard drive has not crashed.3. Based on OS, boot from floppy and re-sys disk, or use CD to repair OS.
What is a firewall?
Describe, genrally, how to manage a firewall
What is a Denial of Service attack?
What is a “spoofed” packet?
What is a SYN Flood?
What do you do if you are a victim of a DoS?
What is GPG/PGP?
What is SSH?
What is SSL? How do you create certificates?
What would you do if you discovered a UNIX or Network device on your network has been compromised?
What would you do if you discovered a Windows system on your network has been comrpromised?
What is DNS Hijacking?
What is a log host?
What is IDS or IDP, and can you give me an example of one?
Why are proxy servers useful?
What is web-caching?
Posted in: Networking
11 Responses to “Security interview questions for network admin”
anju Says: February 28th, 2006 at 4:14 pm
A firewall is simply a program or hardware device that filters the information coming through the Internet connection into your private network or computer system. If an incoming packet of information is flagged by the filters, it is not allowed through.
Firewalls use one or more of three methods to control traffic flowing in and out of the network:
* Packet filtering - Packets (small chunks of data) are analyzed against a set of filters. Packets that make it through the filters are sent to the requesting system and all others are discarded.* Proxy service - Information from the Internet is retrieved by the firewall and then sent to the requesting system and vice versa.* Stateful inspection - A newer method that doesn’t examine the contents of each packet but instead compares certain key parts of the packet to a database of trusted information. Information traveling from inside the firewall to the outside is monitored for specific defining characteristics, then incoming information is compared to these characteristics. If the comparison yields a reasonable match, the information is allowed through. Otherwise it is discarded.
Ranjha Singh Says: November 3rd, 2006 at 10:43 am
DNS Hijacking mean hijacker spoof the ip of any DNS query. Lets example. user send a DNS requset for YAHOO.com and Hijacker hijack this packet & answer on behalf of DNS and give the wrong IP Assres.
Ranjha Singh Says: November 3rd, 2006 at 10:52 am
SSL is Secure Socket Layer. CA Genrates the certificates.
SUNIL ARORA Says: November 3rd, 2006 at 11:02 am
Denial of Service attack means server or machine receive so many packets from the single or multiple network sources or spoofed resources so that its all resources will be used to in responce of those packets & after that it will hang or not responding. Then it will start to denial to its services.
bob saget Says: December 8th, 2006 at 2:29 pm
Why are you answering these questions people? These are questoins for a ‘job interview’ not for you to show off your clearly impeccable grasp of the english language.
virendra yadav Says: May 8th, 2007 at 6:37 am
. FireWall is nothing but it is used to avoid the unwanted trafic or unauthorised entry. The Firewall has 2 types 1. Hardware & 2.Software. Now the most familiar used firewall is PIX from the make of cisco. and other firewalls like nokia and so on..further… as a security measure it also depends on the network designer and implementer that how to use a Firewall mean to say the security measures like how to present the content filtering and Url filtering which type of firewall should be used and where to put it..20d3
Harish P Says: June 5th, 2007 at 7:32 pm
9). What is SSL? How do you create certificates?
Ans : SSL: Secure Sockets Layer, a protocol developed by Netscape for transmitting private documents via the internet. SSL works by useing a private key to encrypt data that`s transferred over the SSL connection. Both Netscape Navigator and Internet Explorer support SSL and many Web sites use the protocol to obtain confidential user information, such as credit card numbers. By convention, Web pages that require an SSL connection start with https: instead of http .
Naveen Says: July 2nd, 2007 at 6:35 am
(1)A firewall is simply a program or hardware device that filters the information coming through the Internet connection into your private network or computer system. If an incoming packet of information is flagged by the filters, it is not allowed through.
Sunil Reddy Says: July 26th, 2007 at 12:53 pm
What is a firewall?
Firewall is a device or a software which restricts the unauthorised accesses to and from the network……….Guys its that simple no need to beat around the bush
CheersSunil Reddy.MSecurity Consultant
deepak kajla Says: September 3rd, 2007 at 1:24 am
ssh=secure shell used for remotely logged in another clint systems through a linux administrator.
DPK Says: November 27th, 2007 at 2:50 am
SSH is a secure way of connecting to a Server or Remote host. This protocols replaces the Telnet applications.
SSH uses 3 different ways of authentications,
1. Preshared Key authentication2. Public/Private key authentication3. Host based authentication
SSHkeygen tool is used to generate Public and Private keys for a host.