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Local Area Network
Questions concerning the setting up, troubleshooting and operation of wired LANs used by businesses and other organizations
4,003 Questions
What advantages does token ring have over Ethernet?
ring topology uses token ring i.e one way communication which passes the token with header and Destination address into the network.If one client in the network just disconectd from the network then the the entire network collapse. For this problem FDDI is used for fault tolorence Where as ethernet works much efficiently in packet delivering
What network model ensures that no computer on the network has more authority than another?
peer-to-peer
- When both ends of a serial WAN link are configured to run the PPP encapsulation method they establish a session based on the 3 steps below:
Step 1
- Link establishment and configuration negotiation
- In this phase LCP opens the connection between the two interfaces and negotiates configuration options. this phase is done once the receiving router sends a configuration-acknowledgment frame back to the router who first initiates the connection...
Step 2
- Link quality determination (optional)
- In this phase LCP tests the link between the routers to determine if the quality is sufficient to bring up the network layer protocol.
Step3
- Network Layer Protocol configuration negotiation
- After step 2 ends, the appropriate NCP can separately configure the network layer protocols, and bring the protocol up and down at any given time. If LCP closes the link between the routers it will inform the network layer protocol so that it can take action in regards to the interfaces.
- TERMS -
PPP = Point-to-Point Protocol
LCP = Link Control Protocol
NCP = Network Control Protocols
- hope this helps :)
- miirii
The DHCP Server keeps all the information and data base about the DHCP Cliencts. And it works as folows. ________ ________ | | <-----D------------> Discover-------------> | | |DHCP | <-----O------------> Offer----------------> |DHCP | |SERVER | <-----R------------> Request--------------> |CLIENT | |________| <-----A------------> Acknowledgement------> |________|
I want further answers regarding this. please do send me.
1. DHCP automatically Discover the systems , 2. Server Send the offer to the client systems ,
3. Client send the Request to Server System,
4. last one Acknowledgement send by Server to Client
I would like to make an amendment to that so that it is somewhat further understood in it's entirety.
1st: Hardware sends a broadcast asking for information regarding DHCP servers within the network (or Sub-net of course).
2nd. DHCP server responds saying "Hey, I'm here!"
3rd. Hardware sends a query for an IP address (not the same as the request phase.)
4th. DHCP server comes back with "Here ya go, you can have xxx.xxx.xxx.xxx if you want it!"
5th. Hardware decides that's what it wants, so it requests a lease for that IP address.
6th. DHCP server acknowledges the request and assigns a lease time to that piece of hardware (identified by it's MAC address).
1st through 3rd is done through MAC as the hardware has no IP address and cannot communicate through IP. To do those communications before the IP addresses are assigned they use UDP packets with Source and Destination MAC addresses as beginning and end-points. And DHCP servers don't discover the hardware added, the hardware discovers the DHCP servers.
That's DORA in a nutshell.
How do you provide security for VPN?
VPN is a security measure of the data transmission. So the weak point would be :
1. How strong is the data transmission encryption.
2. How adequate is the endpoint security.
3. Overall how good is the policy Protection of networks & their services from unauthorized modification,destruction, or disclosure , & provision of assurance that the network performs its critical functions correctly & there are no harmful side-effects.Network security includes providing of data integrity.
Answer Network security comprises the measures a company takes to protect its computer system, and it is a prime concern for every company that uses computers. Compromised network security means a hacker or competitor may gain access to critical or sensitive data, possibly resulting in data loss, or even complete destruction of the system.
Even the owner of the VPN server can not physically see what information is held on its server - as for me it's pretty good security.
However, this does not mean that you should use unverified VPN services.
I use this: boxpn.com and I'm satisfacted- speed and cost is very ok.
And if we talk about security, OpenVPN protocol will help you (by the way, in boxpn, he is present).
What are two characteristics of the data link layer?
Allows the upper layers to access the media using techniques such as framing.
Controls how data is placed onto the media and is received from the media using techniques such as media access control (MAC) and error detection.
What is the Network layer in the OSI?
Layer 7:Application Layer
Defines interface to user processes for communication and data transfer in network
Provides standardized services such as virtual terminal, file and job transfer and operations
Layer 6:Presentation Layer
Masks the differences of data formats between dissimilar systems
Specifies architecture-independent data transfer format
Encodes and decodes data; Encrypts and decrypts data; Compresses and decompresses data
Layer 5:Session Layer
Manages user sessions and dialogues
Controls establishment and termination of logic links between users
Reports upper layer errors
Layer 4:Transport Layer
Manages end-to-end message delivery in network
Provides reliable and sequential packet delivery through error recovery and flow control mechanisms
Provides connectionless oriented packet delivery
Layer 3:Network Layer
Determines how data are transferred between network devices
Routes packets according to unique network device addresses
Provides flow and congestion control to prevent network resource depletion
Layer 2:Data Link Layer
Defines procedures for operating the communication links
Frames packets
Detects and corrects packets transmit errors
Layer 1:Physical Layer
Defines physical means of sending data over network devices
Interfaces between network medium and devices
Defines optical, electrical and mechanical characteristics
What command in the Windows Command prompt will map a network drive?
net use X: //computername/sharingpath
Where X: is the drive letter you want to map, and a sample path would be //MY-PC/sharedfolder
What is one purpose of the TCP three-way handshake?
The three-way handshake in Transmission Control Protocol (also called the three message handshake) is the method used to establish and tear down network connections. This handshaking technique is referred to as the 3-way handshake or as "SYN-SYN-ACK" (or more accurately SYN, SYN-ACK, ACK). The TCP handshaking mechanism is designed so that two computers attempting to communicate can negotiate the parameters of the network connection before beginning communication. This process is also designed so that both ends can initiate and negotiate separate connections at the same time.
How can you set up up local area network?
Setting up computer networking on a home machine is simple, especially if you have a router. You're going to want to synchronize all of the machines on your network with your router and make sure that they all have stable connections. That's all there really is to it.
What is the services and protocol for the following ports port 21 port 25 port 80 and port 110?
21 port - FTP (File Transfer Protocol)
25 port - SMTP (Simple Mail Transfer Protocol)
110 port - POP3 (Post Office Protocol used by email clients)
80 port - HTTP (World wide web Portocol)
Services: port 21- FTP, port 25- Secure shell, Port 80- Web Server and port 110-Web Server
Protocol: port 21-FTP, port 25- SSH, port 80- HTTP and port 110- POP2
Can you connect two wireless Access points?
You can connect to your access point through its default that may be 192.168.2.1 (or some thing ) depending on your device model, Midrar Ullah
VLANs provide the capability so virtually segregate traffic on a network. VLANs work by tagging traffic packets and ensuring that packets with separate VLAN IDs are only available at ports which have been configured for that VLAN ID.
What network topology is mostly used in homes and businesses?
The network in the secondary building should also be star topology. It is the most common and very reliable. There will be twelve desktop computers in the building which should be connected to each other and the main building as well. So there should be Cat 6 cabling used in this building. The other networking equipment needed in the building is a wireless router which will help the mobility of the employees, a networking switch for all the workstations and the wall sockets into which the Ethernet cables will be plugged in. There will also be two sockets for the printers. There will be VoIP phones on the desks with the computers
What was the name of the first network and when was it introduced?
The Advanced Research Projects Agency Network (ARPANET) developed by ARPA of the U.S. Department of Defense was the world's first operational packet switching network, and the progenitor of the global Internet.
In the spring of 1967 at the University of Michigan, ARPA held its yearly meeting of the "principle investigators" from each of its university and other contractors. Results from the previous year's research was summarized and future research was discussed, either introduced by ARPA or the various researchers present at the meetings. Networking was one of the topics brought up at this meeting.
The Completion Report continues the story:
"At the meeting it was agreed that work could begin on the conventions to be used for exchanging messages between any pair of computers in the proposed network, and also on consideration of the kinds of communications lines and data sets to be used. In particular, it was decided that the inter-host communication 'protocol' would include conventions for character and block transmission, error checking and retransmission, and computer and user identification.
The initial ARPANET consisted of four IMPs (Interface Message Processors). They were installed at:
UCLA, where Leonard Kleinrock had established a Network Measurement Center (with an SDS Sigma 7 being the first computer attached to it). The Stanford Research Institute's Augmentation Research Center, where Douglas Engelbart had created the ground-breaking NLS system, a very important early hypertext system (with the SDS 940 that ran NLS, named 'Genie', being the first host attached). The UCSB (with the Culler-Fried Interactive Mathematics Centre's IBM 360/75, running OS/MVT being the machine attached). The University of Utah's Graphics Department, where Ivan Sutherland had moved (for a DEC PDP-10 running TENEX).
The first ARPANET link was established on November 21, 1969, between the IMP (Interface Message Processor) at UCLA and the IMP at SRI. By December 5, 1969, the entire 4-node network was connected
How does the switch learn the Mac address?
Each Ethernet frame sent from one computer to another includes the source and the destionation MAC addresses. It is from these addresses that the switch learns what device is connected to the port.
At first, the switch won't know the destination address; in that case, it will broadcast the frame through all of its ports. But soon it learns this information.
It is also possible, in some switches, to add the MAC address through configuration commands.
If both PCs have ethernet cards, the best cable to use would be a crossover cable. A crossover cable is almost the same thing as a regular ethernet cable, except the wires inside the connector are reversed on one end. This reversing of the wires allows you to connect a crossover cable between two PCs without any other network equipment like a switch or a hub.
What is the difference between process switch and mode switch?
Process switch is switch the process state between the status like read, blocked ,suspend. Mode switch is the switch the process privilege between the mode like use mode, kernel mode. Generally a mode switch is considered less expensive compared to a process switch.
What is the major factor that makes coaxial cable less susceptible to noise than twisted-pair cable?
A coaxial cable is shielded from electrical interference signals whereas UTP (Unshielded Twisted Pair) cable is not. The random twisting with which UTP is manufactured works very well, however, in locations where the interference levels are relatively low, because its method of construction ensures that any interference affects both wires in the pair equally. It should also be mentioned that STP (Shielded Twisted pair) cable is also available and is sometimes specified for LANs (Local Area Networks) instead of coaxial cable. But the much greater volume of coaxial cable sold means that coaxial cable prices have been kept very competitive with STP. As STP tends to be more tricky to install - its shield has to be very carefully and correctly terminated at each end - coaxial tends to be used more than STP where noisier-than-normal interference conditions are present at a particular site. Since the 1990s NIC (Network Interface Card or Component) equipment has had extra logic cicuits within it to reject ambient interference much more effectively than equipment which was designed in the previous 20 years, so nowadays UTP can be used more extensively in locations where only STP or coaxial cable would have had to be used before. So, in relation to LANs in normal non-industrial office and domestic buildings, this exam question is now almost obsolete! However coaxial cable is still necessary to carry LANs in difficult environments such industrial plants; hospitals; undergound railway and road tunnels and mines; on board ships and aircraft, etc. and must also be used to carry signals for radio, televison, video and other applications which run at much high frequencies and bandwidths than LANs.
Technically your question has a lot of unanswered questions: Is this a Windows PC? Is this a home or business ... you see my point? No one can fully answer this question with out knowing the network environment. In general - You need a TAP in the network; a TAP is a secure, known good, point from which to sniff the network traffic; simply trying to use host-based monitoring *may* not work correctly in all cases. Get a copy of WireShark -- get a clean (IE not infected PC) and learn how to use WireShark :) If you have a *lot* of traffic and you wish to *stop* or somehow control the flow of - then get a packet filtering stateful firewall. Or just hire a network security expert.
What is the most common set of protocols used on a local wired network?
The most popular is the TCP/IP suite of protocols
The dns protocol is at what layer of the OSI model?
DNS is an application layer protocol. The application layer of the OSI model is the layer closest to the user and provides network services to the applications of the user. Examples of protocols that operate at the application layer are: DNS, FTP, TFTP, SNMP, TELNET, RLOGIN, SMTP, MIME, NFS, FINGER, BOOTP and SMB.
Do devices connected to the Internet have a unique IP address.?
Yes. Each computer connected to the internet is assigned a unique internet protocol, or IP, address.
How do you use a wireless router?
This is a very hard question to answer because I do not know what router you are on about. Usually, most routers now will have a CD/DVD to help you set up your router.
Basically, what you really need to know when setting up your router is your internet login info, for example; name@dialbb.com. And of course the password. You can get this by phoning your internet provider.
Mapped and/or shared folders on a network allow users to collaborate and share information by modifying the documents in the folders or by putting documents in the folder that is shared without realizing that the folder may not be on their machine, but it looks as though it is.
