Sign Up to our social questions and Answers Engine to ask questions, answer people’s questions, and connect with other people.
Lost your password? Please enter your email address. You will receive a link and will create a new password via email.
Please briefly explain why you feel this question should be reported.
Please briefly explain why you feel this answer should be reported.
Please briefly explain why you feel this user should be reported.
What Is The Purpose Of The Distributed Coordination Function In An Ieee 802.11 Wlan Environment?
What is the purpose of the Distributed Coordination Function in an IEEE 802.11 WLAN environment? For collision detection, the full-duplex mode is used by the DCF. It gives them access to a client to detect whether or not the channel is clear before transmission. For the transferal of the data throuRead more
What is the purpose of the Distributed Coordination Function in an IEEE 802.11 WLAN environment?
Answer: The purpose of the Distributed Coordination Function in an IEEE 802.11 WLAN environment is that It gives access to a client to detect whether or not the channel is clear before transmission.
What is DCF (Distributed Coordination Function)?
Along with the IEEE 802.11 based WLN the distributed coordination function is the important component of the media access control (MAC), which also includes the WIFI. The algorithm which implies the DCF is the backoff algorithm along with the carrier sense multiple access and collision avoidance.
For a DIFS interval and the transmission, listening to the channel status the distributed coordination function needs the station. During the DIFS interval if the channel is busy the station will discard the transmission. in the network when the various stations need the wireless medium, and the several stations sense that the channel is busy and their access is discarded and they found that the channel is free all f them try t send the transmission and the channel may squeeze due to the load and the collision of signals occur .to prevent this the DCF act as the backoff which forces the station to allow its permit to the channel for an extra time.
The length of the DCF backoff period is determined with the help of the following equations:
- DCf has the extra virtual carrier sense mechanism which can exchange the RTS (request-to-send) and the CTS (clear-to-send) frames of the source and destination in the period of the interval of the data packets or frames transmission.
- An acknowledgment mechanism is present in the DCF which ensures when the data is sent toward the destination, the destination needs to send the ACK frames to tell that the source of the transmission is successful.
- The terminal problem either is hidden or the exposure is not thoroughly solved by the DCF only it can reduce the problem burden with the help of the RTS and CTS and gives the advice to use the larger carries sensing range.
- DCF by the default setting of the hardware WIFI is recommended in the IEEE 802.11 metrics.
- The message who has a little knowledge is handled by the 802.11 DCF and it can also use an effective amount of time. Such as the ACK can only take 60 μs for the complete transmission it has also contained a sufficient amount of airtime for the transmission of 3240 bits during the speed of 54 Mbit/s.
- PCF (point coordination function) is the feature that is defined by the IEEE 802.11 standard for extra access act as the network coordination which permits the access point for the management of channel access.
See lessHow Is Traffic Routed Between Multiple Vlans On A Multilayer Switch?
How is traffic routed between multiple VLANs on a multilayer switch? With the help of the physical interface, the traffic is routed. The traffic is routed through internal VLAN interfaces. Traffic is routed through the subinterface. The traffic is broadcast out of all physical interfaces. Answer: ThRead more
How is traffic routed between multiple VLANs on a multilayer switch?
Answer: The multilayer layer switches the inter-VLAN routing with the use of the internal VLAN interfaces. The outer physical interface may receive the traffic but they are not necessary for the routing function. During the routing of the VLANs, the traffic of the broadcast which is received on VLAN will remain on the ports which are the members of that VLAN. For the multiple VLANs on the multilayer switches the sub-interfaces are not suitable.
Multilayer switch
A layer 3 switch is called the multilayer switch a device that connects the switch with the router.it is the same as the traditional switches which have 24 or maybe 48 ports or some SFP-ready ports. The difference between both of them is inside the box in the hardware or software.
The switch has the ASICS which is used for the functionalities of layer 3. the switch has the dedicated hardware for it that’s why it is quicker than the router. The multilayer switch has various IP addresses and it also assists with the static routes and the dynamic routes.
Inter-VLAN routing for the multilayer switch
Along with the router on a stick, the switches sent the traffic to the router and the traffic move back toward the switches by performing the frame rewrite and routing. All the works happen in the layer 3 switches. The switch has the assistance of switch virtual interface (SVIs). which performs the routing.it can act as the physical interface because it has the IP address and also can inject the connected route to the routing table. But for each VLAN only one SVI is present. The routing starts with the switch when the packet is received by the switch in VLAN, which is for layer 2.
Since the SVIs are logical, the MAC address for it is present in the software and not in the hardware. The rewrite operations for the frames are performed in the multi-layer switch, it has the same features as the normal switch and is also connected with other switches which are multilayer.
Configuration of the multilayer switch
For the configuration, the first step is enabling the routing on the multilayer switch and by default, they work as the traditional in case you want to use as the layer 2 switch and for this, a command ip routing is written in the command prompt. But some of the devices have the configuration with multilayer switch by default.
See lessWhat Are Two Examples Of Hybrid Topologies?
What are two examples of hybrid topologies? (Choose two.) Full mesh. Hub and spoke. Tree topology. Partial mesh. Extended mesh. Answer: A hybrid topology as the name suggests it is the mixture and the combination of the different topologies. The two examples of hybrid topologies are the partial meshRead more
What are two examples of hybrid topologies? (Choose two.)
Answer: A hybrid topology as the name suggests it is the mixture and the combination of the different topologies. The two examples of hybrid topologies are the partial mesh and the extended mesh.
Hybrid topology
A fusion of more than two topologies as the mesh topology, bus topology, and ring topology is known as the hybrid topologies. The use of the hybrid topology is based on the need and the implementation of the destined computer, network, and their positions.
For the implementation of the topology physically man different technologies are used because the physical structure is complex for the hybrid topology. The good thing about topology is that it is flexible and allows other topologies to include or remove easily. For the diversity in the network, a hybrid topology is needed.
The configuration of many other topologies also happens in hybrid topology. such as the hybrid network made with star backbone and the ring network and the star mesh hybrid topology is also used in case the main backbone is failed which destroys the whole network.
Let’s discuss the types of hybrid topologies in the following section:
Star-Ring hybrid topology:
The Star-Ring topology is the combination of the star and the ring topology. with the ring, more than two-star topologies are connected through wires. While in the real ring the data comes at the connecting node. The flow of data is unidirectional or bidirectional. in the original ring, the flow is unidirectional and it does not affect the whole network if a node fails.
Star-Bus hybrid
The bus ad the star topology forms the star-bus hybrid topology. More than two-star topologies are connected with the bus with wires. The bus topology acts as the backbone of the network and provides the wire structure.
Hierarchical hybrid topology
The hierarchical hybrid topology is also known as the network tree topology the maximin root of it is known as the parent node and the minimum level is known as the leaf nodes. The next level node is the child node at level three.
Hybrid topology pros and cons
Pros:
Some of the pros of the hybrid topology are described in the following section:
Cons:
- Complexity: with the involvement of different kinds of topology the structure is complex. And the creation of it is very difficult. The configuration of it requires efficiency and thorough knowledge.
- Cost: An equipment and the maintenance of the hybrid topology is expensive, while the structure hubs are used and are quite expensive.
See lessWhich Statement Describes A Characteristic Of A Wan?
Which statement describes a characteristic of a WAN? WAN works in the same geographics as the LAN but has the serials links. For the backbone of the campus, WAN gives the connectivity for the end-user. The services providers own the WAN networks. The WAN connection is considered by the serial links.Read more
Which statement describes a characteristic of a WAN?
Answers: WAN can connect the LAN with the remote branch site LANs and the sites like telecommunication. The service provider owns the WAN networks, and the connection of WAN is made with a serials interface, not with all serial links that have a connection with WAN. The local network is responsible for the end user’s network connectivity in the organization.
What is the wide-area network (WAN)?
WAN stands for the wide-area network and it is the private geographical network that connects various local area networks. LAN is the network for the small group of the computer and many other devices and covers only a small distance, unlike the WAN. The connection which is established due to WAN is among the branch offices, headquarters of the companies, cloud services, and many other facilities. The device which connects the LAN with the WAN is the router, the WAN for companies gives the user access to share the application, services, and various centralized resources. The feature helps to reduce the cost because there is no need to install the same setup and the applications.
The restriction of the geographical area does not apply to the WAN, unlike the LAN. the LAN is set with different numbers of the area and has the connection with WAN which means WAN has not been restricted to any location. The reliable connectivity and the security of the WAN are provided by the virtual private network or VPN. for different use different VPNs is used. The IPsec VPN is for the open site-to-site connection between the branch and the main office For remote access by individual users, SSL VPN is essential because the data is encrypted over the WAN. Fiber optics is used for the connectivity of the WAN site and the performance, reliability, security of it are more than the VPN but for some of the organizations, it is costly.
How many types of WAN connections are present?
WAN consists of both the wired and the wireless connection. the wire connection of the WAN is described in the following:
the types of wireless WAN are either the cellular data network as the 4G LTE and the WIFI or the satellite links in the network. The wired connection of the LAN is most preferable in most organizations but the wireless technology of the WAN as 4G LTE is increasing in today’s world.
Examples of the WAN:
Some of the examples of the WAN are given in the following sections:
- a network of the bank cash system.
- The network of the organization has several branches.
- The network of the school through the internet.
- WAN which is linked with the internet.
See lessWhat Are Two Load-Balancing Methods In The Etherchannel Technology? (Choose Two.)
What are two load-balancing methods in the EtherChannel technology? (Choose two.) The combination of the source port and the destination port to the internet protocol IP. From the IP of the source to the IP of the destination.From the MAC address of the source to the destination MAC. From the sourceRead more
What are two load-balancing methods in the EtherChannel technology? (Choose two.)
Answer: On the base of the platform like the hardware more than one load-balancing method is used or implemented. The methods are the From the IP of the source to the IP of the destination and the MAC address of the source to the destination MAC beyond the physical links.
The web server overload is a risk to any kind of business no one wants to take a risk because the disturbed network affects the performance of the operation at works and many other services related to the business .it will also have an impact on the end user’s experience with the provides services. That’s why it is necessary to have more than one server which can balance the traffic load and the load balancing methods are effective in this kind of discussion.
Load balancing:
Moreover, load balancing has been used the balance the traffic load on the server among the pool of the servers .it is kind of the cops for virtual traffic that route the request of the client across the server and make them respond faster with efficiency. The main purpose is to make sure none of the servers is overloaded with the work and maintain their performance and efficiency. When the server is down with load then the load balancing methods redirect the load toward the other server that is online at that time. The new server work is to maintain the balance of the traffic when it is added to the server’s pool.
Techniques of the Load Balancing
As many kinds of services are present to lessen the load on the servers than at that time the choice of the algorithm is very important because each will have its strength and the weakness than it is all up to you to choose which kind of technique is useful at the situation according to the network status. Let’s see one of them below:
Round Robin:
Round robin has a simple way to maintain the load and keep balance among the servers. Many same kinds of servers are used for the same services. Each f them are using the same domain name but the IP address are varying. as DNS is responsible for the IP address and domain name storage, when the request of the specific IP address with the domain name is received, the address moves back in a rotating manner.
Weighted Round-Robin:
In the weighted round-robin, the server is appointed according to the number which is assigned to them and the request is sent according to the order.
Least Connection:
The load on the present server will be accounted for in this method. The request will be sent toward the server that has fewer active requests at the time.
See lessWhich Statement Describes A Characteristic Of The Traceroute Utility?
Which statement describes a characteristic of the traceroute utility? The traceroute utility sends the four Echo requests. The ICMP source quench message is used by the traceroute utility. The routes in the path from the source to a destination host are determined by the traceroute utility. The hostRead more
Which statement describes a characteristic of the traceroute utility?
Answer: The utility forms the hops list and the routes in the path from the source to a destination host are determined by the traceroute utility as well.
What is a traceroute?
The utility determines the route which acts as the specified gateway for each hop with the help of the computer from the user PC or source to the destination PC. The time taken by the hops is also estimated by it. The traceroute is effective in determining the internet problem and provides thorough information on the internet as well. The ping is the competitive utility against the traceroute which checks the availability of the host in the network.
The operating systems which are involved in the traceroute are the Windows-based operating system and the UNIX-based as well or maybe it is a part of the protocol as a TCP/IP package. You can download the utility on your computer from many of the sites which offer them for free of cost.
Working of the traceroute
When the command of the traceroute enter in the prompt, then the utility provokes the package dispatch process with the help of ICMP protocol and the packet has the time limit value or TTL which is formed by increasing the first router that receives the packets and returns the message of the exceed time.it can help the router to find the time limit of the hop for the router.
The time limit will increase and this time the packet will receive at the second router, which returns the exceeded message, and so on. The traceroute tells the time taken by the packet as well as the destination. When the packet is received the unreachable message comes back which tells the time limit of the last hop. With the progress of the utility, it can display the records hop by hop. the measurement limit for each hop is three and when the asterisk sign displays it means the limit is exceeded.
The traceroute in the windows operating system is described in the following:
- Click on the START.
- Tap on programs.
- Click the MS-DOS Prompt.
- open the C: WINDOWS prompt.
- Enter tracert http://www.xyz.com or any domain name which is given to the destination PC. the numeric IP address is also entered because they have some importance.
See lessRefer To The Exhibit. R1 Is Configured For Nat As Displayed. What Is Wrong With The Configuration?
Refer to the exhibit. R1 is configured for NAT as displayed. What is wrong with the configuration? NAT-POOL2 is not bound to ACL 1. The NAT pool is not right. The misconfiguration of the Access-list 1. Interface Fa0/0 should be identified as an outside NAT interface. Answer: the R1 needs to have NATRead more
Refer to the exhibit. R1 is configured for NAT as displayed. What is wrong with the configuration?
Answer: the R1 needs to have NAT-POOL2 bound to the ACL 1. This task is completed with the command R1(config)#ip nat within the source list 1 pool NAT-POOL2 .it will give access to the router to check the interesting traffic whether it is matched with the ACL 1 if yes then it would translate with the use of the NAT-POOL2 address.
What is NAT (Network address translation)
For access to the internet, one specific IP address is necessary but we can use the private IP address for our private network. NAT is designed so that multiple devices can use the same IP address if it is necessary. Mostly NAT works on the router or the firewalls.
For access to the lost host, the NAT is used to convert one or more local IP addresses to the Global IP address it can also translate the port number such as it can mask the port number of one host from the other host, within the packet which is forwarding toward the destination. The IP address entries and the port number are listed in the NAT table.
NAT working
The work begins with the gateway selection which sits among two local networks: the internet network and the outside network. The inside network is usually assigned the IP addresses which cannot route to an external network. Some of the external IP addresses are allocated to the gateway. The work of the gateway is to give the valid external address to the traffic which is coming from the system inside. The coming traffic point at the reliable external address and move toward the destined internal system.
The process is concerned with security, and the reason is that the incoming and the outcoming request has to move with the procedure of the translation which gives the offer to certify and authenticate the coming streams and match with the departing request.
Pros of NAT:
Cons of NAT
- The translation in switching causes the delay.
- When the NAT works some of the applications will not work.
- Due to the NAT, the router should not tamper with the port numbers.
See lessRefer To The Exhibit. What Can Be Concluded About Network 192.168.4.0 In The R2 Routing Table?
Refer to the exhibit. What can be concluded about network 192.168.4.0 in the R2 routing table? Along with the summary LSAs, the network was learned from an ABR. With the GigabitEthernet0/0 interface, the network is reached. The network was learned from a router within the same area as R2. It can moRead more
Refer to the exhibit. What can be concluded about network 192.168.4.0 in the R2 routing table?
Answer: the label O defines in a network that the route which is displayed by another router is present in the area together, in the routing table. And in the scenario, the exit
interface is GigabitEthernet0/1.the assigned O IA determine that the entry was from the interarea LSA which forms from an ABR. while the label O*E2 determines the outside networks. in this case, the network designation 0.0.0.0/0 determines that the outer network is the route for the traffic which moves to an external network and the setting is by default.
192.168.4.0 network
The private IP address 192.168.4.0 is designed for the internal private network.it is used by routers, modems, and many kinds of devices. The router admin password and the login IP 192.168.4.0 is the IP address that is used by the router and they act as the gateway of the point of access. The router within the IP address is given access to the administrator of the network to determine their networks etc. On can maintain the security, network IP QoS DNS, proxy, LAN DSL, WAN, WPS, and many other options. Let’s check about the Router admin login in the following section:
The IANA registers the IP address 192.168.4.0 as the private address for a private network 192.168.4.0/24.in the private region the IP address is not designated with any specific organization and everyone might use the IP address without any permission of the regional internet registry which is shown in RFC 1918, and it is different from the local or public IP address. The access to the admin page happens by writing the 192.168.4.0 in the web browser bar and checking the log in detail in the display table.
Steps to the login
The software router modification might happen with access to the admin router through the 192.168.4.0 IP address. The steps for the login are defined in the following:
- For the configuration change the setting or modify the password of the router you want to login. Type the 192.168.4.0 address in the URL of the browser.
- If an error displays it shows that 192.168.4.0 is not the correct IP address of the router .type with an autocomplete.
- If you are not able to change the username or password which is the default the try to cope up with the password given to you by default.
See lessWhat Is The Purpose Of The Passive-Interface Command?
What is the purpose of the passive-interface command? The updates which are missed out of an interface the passive-interface permits to forward them. Permit them to the router to send the updates on an interface but not be able to receive them with an interface. The interface has the permit to remaiRead more
What is the purpose of the passive-interface command?
Answer: The purpose of the passive-interface command is to Permit the router to send the updates on an interface but not be able to send them with an interface.
What is a passive-interface command?
The passive-interface command is used to tell the interface to listen to the routes of RIP or IGRP but not broadcast them. to disable the ability to broadcast on the interface the router assigned to” just listen but don’t talk”. The command help to lessen the load on the CPU by minimizing the interface numbers which are protocol used for communication. The command blocks the processing of routes for the OSPF or EIGRP. Carefully use the command when you don’t want the routing protocols to talk to a specific interface.
Reasons to enable the passive-interface command
When the interface is enabling near the EIGRP network, the network might try to make the adjacency with the neighbor’s router and make it send and receive the update of its network. The command work to prevent the adjacency of the neighboring network.The reason for the passive command work is described below:
Configuration and verification of the command
The interface router configuration can block the transmission of the EIGRP hello packets with help of the commands:
According to the reference topology the router 0 is no need to move the RIP updates to the interface LAN, rather it the router 0 is sending the updates to the computers connected LAN .it can be verified by allowing a debug on Router 0 with command <debug ip rip> in the privileged exec mode. The verification can be also with the show ip protocol command
The fast Ethernet 0/0 as passive interface and connect with LAN is configured. The process is described in the following:
The interface is also configured for the dynamic protocol. The configuration is canceled with the <interface-id> command. The default command can also configure the passive-interface.
See less5. What Do Rfc 349 And Rfc 1700 Have In Common?
What do RFC 349 and RFC 1700 have in common? Answer: The RFC 349 and RFC 1700 both have the assignment number and they have a wide function to perform. They provide the application which gives the link, socket .port, and different protocols. What do you know about RFC? RFC stands for “request for coRead more
What do RFC 349 and RFC 1700 have in common?
Answer: The RFC 349 and RFC 1700 both have the assignment number and they have a wide function to perform. They provide the application which gives the link, socket .port, and different protocols.
What do you know about RFC?
RFC stands for “request for comments” it is a document which describe by the internet engineering task force (IETF) and it is due to the drafting and the views of the interested parties. It gives a lot of information. For those who want to become the internet standards, the end version of an RFC becomes the standard and no further changes are needed to execute. The document describes the standard since 1969.
About 2400 requests for comments (RFCs) are printed on different protocols, process applications, and concepts. A protocol like TCP/IP is formed by agreement rather than the committee. The ISOC member submits the FRC for acceptance and the submission of the documents done with the IETF. The RFC after the publication has the classification described in the following sections:
As the RFC is published it went through many tests and discussions by groups and individuals.it can go through different stages of development:
RFC Sub-series
The series of the RFC has three-subseries RFCs: BCP FYI and STD. the best practice BCP is the mandatory sub-series of IETF and not of the standard tracks. While the FYI is a sub-series of informational RFC which is encouraged by the specific RFC 1150. the STD is the third sub-series of the specific RFC 2026.
Streams of RFC
There are four RFC streams: IETF, IRTF, IAB, and Independent Submission. Only the IETF creates BCPs and RFCs on the standards track. The IESG oversees an independent dispatch for conflicts with the work of the IETF; quality is assessed by an independent editorial board. In other words, independent IRTFs and RFCs are supposed to contain information or experiences relating to the Internet in general that do not conflict with the work of the IETF; compare RFC 4846, RFC 5742, and RFC 5744.
Some of the RFCs with their title are described in the following:
- RFC 20: ASCII format for Network Interchange.
- RFC 42: Message Data Types.
- RFC 768: User Datagram Protocol.
- RFC 791: Internet Protocol.
See less