Article for BASIC NETWORKING QUESTIONS :: [ PART-1]

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What is difference between baseband and broadband transmission?

In the 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.

In baseband transmission we transmit digital signal without converting it into analog, here a low pass channel is used.

In broadband transmission we transmit digital signal by converting it into analog. Here a band pass channels used.

What are 10Base2, 10Base5 and 10BaseT Ethernet LANs?

10Base2?An Ethernet term meaning a maximum transfer rate of 10 Megabits per second that uses baseband signaling, with a contiguous cable segment length of 100 meters and a maximum of 2 segments.

10Base5?An Ethernet term meaning a maximum transfer rate of 10 Megabits per second that uses baseband signaling, with 5 continuous segments not exceeding 100 meters per segment.

10BaseT?An Ethernet term meaning a maximum transfer rate of 10 Megabits per second that uses baseband signaling and twisted pair cabling.

All these 3 are related to Ethernet cables, where 10base2 can define as maximum rate of data transfer is 10megabits per second ,B stand for baseband signaling and 2 is for 200 meter of length… this is same for 10base5 but where in 10baset T stands for twisted pair of cable

How to create vlan

a VLAN is a broadcast domain created by switches. Normally, it is a router creating that broadcast domain. With VLAN?s, a switch can create the broadcast domain. This works by, you, the administrator, putting some switch ports in a VLAN other than 1, the default VLAN. All ports in a single VLAN are in a single broadcast domain.Because switches can talk to each other, some ports on switch A can be in VLAN 10 and other ports on switch B can be in VLAN 10. Broadcasts between these devices will not be seen on any other port in any other VLAN, other than 10. However, these devices can all communicate because they are on the same VLAN. Without additional configuration, they would not be able to communicate with any other devices, not in their VLAN.

VLANs are created on Layer 2 switches to control broadcasts and enforce the use of a Layer 3 device for communications. Each VLAN is created in the local switch’s database for use. If a VLAN is not known to a switch, that switch cannot transfer traffic across any of its ports for that VLAN. VLANs are created by number, and there are two ranges of usable VLAN numbers (normal range 1-1000 and extended range 1025-4096). When a VLAN is created, you can also give it certain attributes such as a VLAN name, VLAN type, and its operational state. To create a VLAN, use the following steps.

1) Configure VTP. VTP is a protocol used by Cisco switches to maintain a consistent database between switches for trunking purposes. VTP is not required to create VLANs; however, Cisco has set it up to act as a conduit for VLAN configuration between switches as a default to make administration of VLANs easier. Because of this, you must first either configure VTP with a domain name or disable VTP on the switch.

2) Create the VLAN. VLANs are created by number. The two ranges of VLANs are as follows: The standard range consists of VLANs 1 to 1000. The extended range consists of VLANs 1025 to 4096.Extended VLANs are currently supported only on switches running COS software version 6.1 or greater. When you create a VLAN, you have many options to consider. Many options are valid only for FDDI and Token Ring VLANs. Some of the items configured deal with options, such as private VLANs, which are discussed in other sections in this book. VLANs are created using the set Vlan command for COS devices or with the Vlan command in Vlan database mode for IOS switches.

Explain What is an Access Point (AP)?

An access point or AP is the infrastructure device that contains a wired network interface and one or more radio interfaces that bridges data between the air and the wire. Its is a gateway between wire network & wireless network

Explain LAN?

LAN is a computer network that spans a relatively small area. Most LANs are confined to a single building or group of buildings. However, one LAN can be connected to other LANs over any distance via telephone lines and radio waves. A system of LANs connected in this way is called a wide-area network (WAN). Most LANs connect workstations and personal computers. Each node (individual computer) in a LAN has its own CPU with which it executes programs, but it also is able to access data and devices anywhere on the LAN. This means that many users can share expensive devices, such as laser printers, as well as data. Users can also use the LAN to communicate with each other, by sending e-mail or engaging in chat sessions.

How can I increase the number of LAN ports on a router?

In general, you can connect any switch/hub to a router in order to expand the number of Ethernet devices connected to it.

If the hub/switch you want to connect has an Uplink port, all you need is to use normal patch cable, plug one end to the Uplink port (it can be on either device) and the other to any regular port on the other device. Note that if both devices have an Uplink port, you should not connect them to each other!

If neither device has an Uplink port, you most likely need to use a Crossover cable and plug it into any port on both the router and the switch/hub.

Note: Some newer routers have Auto-MDI/MDIX (or auto-crossover) LAN ports, meaning they are capable of automatically detecting what type of device is being connected and work with either.

what are the advantages of STP over RSTP?(not RSTP over STP) This question asked in TCS

The addition of the word rapid should already be a hint on how RSTP improves on STP. In STP, if the topology changes either because of a new link added or a link lost, it can take anywhere between 30 to 50 seconds in order to adapt to the new topology and provide the least cost path. With RSTP, that is reduced to three hello times, which has a default value of 2 seconds for a total of 6 seconds. The ability to adapt new topologies is very advantageous especially when dealing with high volume traffic in order to avoid lost packets

STP is the basic standard and so is compatible with all versions (including PVST and PVST+)

Explain What are NETBIOS and NETBEUI?

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

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

Tell us is a WLAN secure?

YES! WLANs use much of the same technology (and even more in cases) that makes digital PCS phones secure. Spread spectrum and frequency hopping was originally developed for military use. The technology was designed to keep prying enemy ears from intercepting highly sensitive data. Both of these technologies are used in virtually all WLAN applications.

Besides making the radio link secure, the data is also encrypted for even more security if the radio link were ever? Tapped? Different equipment manufacturers have implemented 40 bit, 64bit and 128 bit encryption. This initial attempt at security had some weaknesses, which were quickly identified.

New enhancements known as? Wi-Fi Protected Access? (WPA) greatly improve the security of WLAN links. The two primary areas of improvements are in the areas of data encryption and user authentication.

The new encryption technique TKIP (Temporal Key Integrity Protocol) addresses all the known vulnerabilities of the previous WEP encryption technique by? Wrapping? A very secure protective layer over the existing WEP packets.

WEP had virtually no user authentication mechanism in it?s initial deployment. WPA coupled with another authentication technique EAP (Extensible Authentication Protocol) provides the mechanism for true authentication services. This not only authenticates the user at login, but also protects the user from accidentally joining an un-wanted rogue network, which may steal network credentials.

Additional layers of security can be supported through virtual private networks (VPN), radius servers, and other techniques.

In which OSI layer does a telecom sector stand for ?

Telecom sector comes in layer3 that is network layer.

What is Remote Procedure Call (RPC)?

RPC hides the intricacies of the network by using the ordinary procedure call mechanism familiar to every programmer. A client process calls a function on a remote server and suspends itself until it gets back the results. Parameters are passed like in any ordinary procedure. The RPC, like an ordinary procedure, is synchronous. The process that issues the call waits until it gets the results.

Under the covers, the RPC run-time software collects values for the parameters, forms a message, and sends it to the remote server. The server receives the request, unpack the parameters, calls the procedures, and sends the reply back to the client. It is a telephone-like metaphor.

A Remote procedure call (RPC) is an inter-process communication that allows a computer

program to cause a subroutine or procedure to execute in another address space (commonly on another computer on a shared network) without the programmer explicitly coding the details for this remote interaction. That is, the programmer writes essentially the same code whether the subroutine is local to the executing program, or remote. When the software in question uses object-oriented principles, RPC is called remote invocation or remote method invocation.

Note that there are many different (often incompatible) technologies commonly used to accomplish this

List out the benefits obtained by using the Client/Server oriented TP Monitors?

* Client/Server applications development framework.

* Firewalls of protection.

* High availability.

* Load balancing.

* MOM integration.

* Scalability of functions.

* Reduced system cost.

What is FISH in Computer Networks

Files transferred over Shell protocol (FISH) is a network protocol that uses Secure Shell (SSH) or Remote Shell (RSH) to transfer files between computers and manage remote files.

What is CIDR?

Classless Inter-Domain Routing CIDR is a new addressing scheme for the Internet which allows for more efficient allocation of IP addresses than the old Class A, B, and C address scheme.

What is RIP what is the use of RIP?

RIP (routing information protocol)is a distance vector dyanamic routing protocol. It is used where we have less no. of routers. Its max hop count is 15. It broadcast its entire routing information in every 30 seconds. It is a class full routing protocol.

RIP version 2 is a classless routing protocol. Although RIP is still actively used, it is generally considered to have been made obsolete by routing protocols such as OSPF and IS-IS. Nonetheless, a somewhat more capable protocol in the same basic family (distance-vector routing protocols), was Cisco’s proprietary (IGRP)

How does Asynchronous Transfer Mode (ATM) work?

ATM works by transmitting all traffic in small, fixed-sized cells. These small, fixed-size cells reduces queuing delay and can be switched quickly. ATM fits into layer 2 of the OSI model and provides functions for framing and error correction. At the port interface, ATM switches convert cells into frames, and vice versa. ATM provides Quality of Service and traffic shaping.

ATM (asynchronous transfer mode) is a dedicated-connection switching technology that organizes digital data into 53-byte cell units and transmits them over a physical medium using digital signal technology. Individually, a cell is processed asynchronously relative to other related cells and is queued before being multiplexed over the transmission path.

Because ATM is designed to be easily implemented by hardware (rather than software), faster processing and switch speeds are possible. Speeds on ATM networks can reach 10 Gbps. Along with Synchronous Optical Network (SONET) and several other technologies, ATM is a key component of broadband ISDN (BISDN).

How inter vlan communication takes place in a layer 3 switch. Also the configuration details.

In Vlans every Vlan is assigned a Vlan Id and vlan to communicate require a Router between them as every Vlan is in different network .They can also have a Trunk configured so that there traffic can flow between them.

how many type of routing protocols? how perform these protocols? how can define?

2 Types

1. Static

2. Dynamic

Under Dynamic,

1. Distance vector

2. Link state

Under Distance Vector,

1. RIP

2. IGRP

3. RIP V2

4. BGP

Under Link State

1. OSPF

2. IS-IS

EIGRP is hybrid.

What is the difference between TCP and IP

Transmission control protocol is the set of protocol which is responsible for the delivery of the data to the correct destination over the network and it is the connection oriented protocol. and IP is the set of rules which is used to communicate two host on the network or we can say that ip is the logical address of the particular machine of the network.

What is the difference between Client and desktop Operating systems?

Desktop operating system is a standalone operating system, able to perform all operations and requests independently. Client o/s cannot do that, moreover client uses all s/w via requests to servers. A node connected to server (Linux concept).

What is the difference between Unshielded twisted pair(UTP) and Shielded twisted pair(STP) ?

A pair of unshielded wires wound around each other is known as UTP. An UTP is a pair of copper wires wound by plastic insulator. UTP is the chipest form of the cables available for networking purposes. It is highly use in local area network LAN environment. And Shielded twisted pair (STP) is a pair of wires wound around each other and each pair is placed inside a protective foil wrap to protect it from crosstalk. These wires are placed in an outer copper braid to protect it from external interference. STP can use in environment that are near electrical units and radio towers. In data communications there is a cable type called FTP (foil shielded pairs) which consists of four twisted pair inside one common shield (made of aluminium foil).

What is the bandwidth of a Switch and A Hub?

Bandwidth is the amount of traffic transferred between two systems. Hub is Half Duplex it supports 10 mbps. Switch Is half duplex and full duplex it supports 10/100/1000 mbps

Why we use cross cable to connect same devices?

Same devices like PC-2-PC, it uses(NIC for PC) 1,2 for transmission & 3,6 for reception. If we don’t use cross cable then we can’t transfer data.

While in the case of switch/hub they receive (NIC of SWITCH/HUB)data on 1,2 & transmit on 3,6. Thats why we use straight cable for de-similar host & cross cable for similar hosts.

What do you mean by Twisted-pair Cabling ?

A twisted Piar cable is made of two insulated wires twisted together to reduce the effects of outside noise and crosstalk interference.

twisted Pair cable comes in two forms

(1) Unshielded

This cable is the most common type of telecommunication medum in use today

Its frequency range is suitable for transmitting both data and voice.

(2) Shielded

This cable has a metal foil ro braired mesh covering that encases each pair of insulated conductors The metal casing prevents the penetration of electromagnetic noise.

STP installation in more difficult than UTP, Because the shield must be connected to a ground .

What is the difference between L3 Switch and Router, If they Perform the same function why we need both of them?

Layer 3 switches do routing with ASIC chips. Routers do it with a microprocesor and its associated software. Therefore the Layer 3 switches are much faster than traditional routers, but cost more. We need them both because in many situations a slow router is sufficient and cheaper than a gigabit layer 3 switch router.

When we use multiple subnets in an organization, then a switch can do the routing between the subnets internally much faster than an external router, because the switch doesnt have to send the packets to another device. another important reason why should we must use a router is the position where we use the router. The router is supposed to sit in between your private network and the public network then it is not wise using a switch here because it will expose your private network in to the public network

What is router and how it works explain it?

A router is equipment that creates a link between different networks or sub networks. Routers “route” data from a LAN to another router, then another router until the data reaches the destination.

Routers are traffic cops, permitting only authorized machines to send data to the local network so that privacy of information is maintained. Also the router can keep a tab of network usage statistics, handle security issues and also keep a tab on the errors.

When you send an email to your pal on the other side of the country, it is the routing technology that makes sure that he or she gets the message and not every other computer that is connected online.

Router directs the flow of traffic among networks. For example, let’s suppose that a company’s web designers writers. The two subdivisions are linked with a router. A router links the two networks onto the internet. The router is the device on the network that sees each message sent by any computer on either network. When a web-designer sends a file to a colleague, the router looks at the recipient’s address and keeps that part of the traffic solely for that particular LAN. On the other hand, if the web designer wants to ask the HR department about appraisals, the router diverts that piece of traffic through the HR department.

What is meant by Middleware?

Middleware is a distributed software needed to support interaction between clients and servers. In short, it is the software that is in the middle of the Client/Server systems and it acts as a bridge between the clients and servers. It starts with the API set on the client side that is used to invoke a service and it covers the transmission of the request over the network and the resulting response.

It neither includes the software that provides the actual service – that is in the servers domain nor the user interface or the application login – that’s in clients domain.

How many layers in networking?

In networking 7 layer of OSI model:

Application

Presentation

Session

Transport

Network

Data Linnk

Physical

5 layer of TCP/IP model:

Application

Transport

Network

Data Link

Physical

3 layer of cisco model:

core layer

distribution layer

access layer

What is RAID in ccna?

A method used to standardize and categorize fault-tolerant disk systems. RAID levels provide various mixes of performance, reliability, and cost. Some servers provide three of the RAID levels: Level 0 (striping), Level 1 (mirroring), and Level 5 (striping & parity).

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Tauseef Emraj Shehan

4 Comments

  1. sorfuddin ahmad
    sorfuddin ahmad on

    thanks for your post about this Article,this articles is effective in our real life

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