For what two purposes does the Ethernet protocol use physical addresses? (Choose two.)
A. to uniquely identify devices at Layer 2
B. to allow communication with devices on a different network
C. to differentiate a Layer 2 frame from a Layer 3 packet
D. to establish a priority system to determine which device gets to transmit first
E. to allow communication between different devices on the same network
F. to allow detection of a remote device when its physical address is unknown
Answer: AE
In an Ethernet network, under what two scenarios can devices transmit? (Choose two.)
A. when they receive a special token
B. when there is a carrier
C. when they detect no other devices are sending
D. when the medium is idle
E. when the server grants access
Answer: CD
Monday, 1 May 2017
Tuesday, 23 August 2016
Pass4sure 200-120 Question Answer
Host A is communicating with the server. What will be the source MAC address of the frames received by Host A from the server?
A. the MAC address of router interface e0
B. the MAC address of router interface e1
C. the MAC address of the server network interface
D. the MAC address of host A
Answer: A
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A. the MAC address of router interface e0
B. the MAC address of router interface e1
C. the MAC address of the server network interface
D. the MAC address of host A
Answer: A
200-120 BrainDumps
400-101 Exam Dumps
Cisco Real Exams Dumps
Wednesday, 13 July 2016
Cisco Will Help Us Solve The LoT Data-Delivery Problem
Being bought out by Cisco will only aid Jasper in its bid to simplify IoT connectivity for a wider range of mobile providers and enterprises, it has said.
Cisco's $1.4 billion acquisition of cloud-based Internet of Things (IoT) platform Jasper will enable the latter to continue its bid to solve the problem of data delivery for mobile providers, and taking the complexity out of IoT for enterprises.
Calling Jasper the "technical interface" for the more than 30 mobile operator groups for which it provides an IoT platform, Macario Namie, head of IoT Strategy for Cisco Jasper, said Jasper was founded 12 years ago to solve one major problem: Enabling enterprises to put connected products on mobile networks worldwide.
"For us, being part of Cisco, number one we still very much believe that the opportunity that existed for us as an independent business is just even that much greater," Namie told ZDNet.
"One of the things that most excites us about being part of Cisco -- we can address the bigger problem now that we're part of a larger organisation -- is that getting the data off of the sensor and into the cloud wherever that is for the enterprise is a hard problem.
"It's a communications problem, it's a plumbing problem, it's a speciality problem; you're talking about various different technologies in terms of network, for devices if there's 100 devices, you have 99 operating systems, so it's incredibly fragmented, and so most organisations not only don't have a competency of how to connect things ... more importantly, they don't want that competency, they just want everything to work."
Providing a simple solution that works well for both enterprises and mobile providers is Jasper's overall goal, Namie added.
"We want to solve that data-delivery problem and just work super easy for the customers," he said.
"Our job is to remove the complexity and make it as simple as possible, across the network, whether cellular, whether it's wired, whether it's in a moving device, whether it's in a static device."
Included among its mobile operator customers are AT&T, which earlier this week launched an IoT Starter Kit developed with Cisco; all three Canadian operators; two of Japan's three operators; China Unicom, with Namie noting that China is a rapidly growing market for IoT; several operators across Europe; Etisalat in the United Arab Emirates; and Telstra, which he said is "very serious" about its network, and Optus in Australia.
More importantly, according to Namie, Jasper serves over 5,100 enterprises across these mobile networks. With 32 million devices connected to its platform, and growth of over 1 million more devices each month, he said Jasper's current IoT product is in its "hyper-growth stage".
Jasper supplies the cloud-based software-as-a-service control centre that sits between mobile providers and enterprise customers wanting IoT connected solutions, with the control centre providing access via either the web or application programming interfaces (APIs) to control turning the service on, rate plans that customers are assigned to, the policies involved, usage monitoring, reporting, and fraud controls.
Jasper's product currently utilises the existing cellular networks; however, it is actively looking into low-power wide-area (LPWA) networks such as LoRa, as well as enterprise Wi-Fi, which Namie recognised as being "a big part of Cisco".
"Most of the operators are actually looking at low-power wide-area networks as well," he added.
"There's a little bit of debate in our world over whether unlicensed spectrum models like LoRa, what their role is compared to some other ones that are cellular based, like narrowband IoT, or LTE Cat M or Cat 1."
The arguments in favour of narrowband IoT focus on the fact that it is supported by the existing cellular networks, with instant nationwide coverage after a software upgrade, and that it also utilises the existing spectrum, meaning there will be no debate about allocating a spectrum band and regulating that.
"The biggest fear is just interference and noise," Namie explained in relation to the cons of using LPWA for IoT.
"So if you believe, as some of us do, that maybe not next week or next year, but there will ultimately be billions of devices connected, and there's a role for LPWA in that, then you can have a lot of signal interference and congestion ... and so that has to be managed. I don't think people have addressed that well enough yet.
"That's one argument for licensed spectrum -- because it can be controlled that way -- but then it has to be governed and it becomes very expensive, which is the flipside to it. I don't know that there's a great answer on it yet."
During his Cisco Live Las Vegas keynote on Monday morning, Cisco CEO Chuck Robbins said the acquisition of Jasper had been "critically important" to the networking giant's overarching strategy.
According to Robbins, an IoT strategy is one of the things required for companies, governments, and the enterprise to take part in digital transformation, alongside executive sponsorship; speed, agility, and innovation; IT and line-of-business alignment; and pervasive security.
Robbins said Cisco is in a unique position for monetising IoT by using its skill set in and knowledge of both service providers and the enterprise.
"One of the fundamental things that I believe ... is that one of our advantages is our deep understanding of the service provider environment and the enterprise environment, and our ability to help bridge those two," the chief executive told media on Monday.
"Which is why Jasper is such a great fit for us, because it is a technology that we acquired, but it's one that we partner with the service provider to actually drive that connectivity, and we're looking at how we not only provide value to the enterprise by giving them the ability to leverage that data into their applications and make decisions, but we're also at the same time looking at how do we provide more services for the service provider to offer on top of that platform, so we look at it from both angles."
Friday, 10 June 2016
Pass4sure 200-120 Question Answer
Which of the following correctly describe steps in the OSI data encapsulation process? (Choose two.)
A. The transport layer divides a data stream into segments and may add reliability and flow control information.
B. The data link layer adds physical source and destination addresses and an FCS to the segment.
C. Packets are created when the network layer encapsulates a frame with source and destination host addresses and protocol-related control information.
D. Packets are created when the network layer adds Layer 3 addresses and control information to a segment.
E. The presentation layer translates bits into voltages for transmission across the physical link.
Answer: A, D Passleader 200-120 Question Answer
A. The transport layer divides a data stream into segments and may add reliability and flow control information.
B. The data link layer adds physical source and destination addresses and an FCS to the segment.
C. Packets are created when the network layer encapsulates a frame with source and destination host addresses and protocol-related control information.
D. Packets are created when the network layer adds Layer 3 addresses and control information to a segment.
E. The presentation layer translates bits into voltages for transmission across the physical link.
Answer: A, D Passleader 200-120 Question Answer
Wednesday, 6 April 2016
Pass4sure 200-120 Question Answer
A network interface port has collision detection and carrier sensing enabled on a shared twisted pair network. From this statement, what is known about the network interface port?
A. This is a 10 Mb/s switch port.
B. This is a 100 Mb/s switch port.
C. This is an Ethernet port operating at half duplex.
D. This is an Ethernet port operating at full duplex.
E. This is a port on a network interface card in a PC.
Answer: C
A receiving host computes the checksum on a frame and determines that the frame is damaged. The frame is then discarded. At which OSI layer did this happen?
A. session
B. transport
C. network
D. data link
E. physical
Answer: D
A. This is a 10 Mb/s switch port.
B. This is a 100 Mb/s switch port.
C. This is an Ethernet port operating at half duplex.
D. This is an Ethernet port operating at full duplex.
E. This is a port on a network interface card in a PC.
Answer: C
A receiving host computes the checksum on a frame and determines that the frame is damaged. The frame is then discarded. At which OSI layer did this happen?
A. session
B. transport
C. network
D. data link
E. physical
Answer: D
Wednesday, 30 March 2016
Arista Comes For Cisco’s Routing Franchise and Bulls Love It
The Street today is contemplating the announcement yesterday by networking equipment firm Arista Networks (ANET) of a new line of switch-routers, the “7500R,” which it claims is adept at transporting bits at 100 billions bits per second and handling large routing tables, and which it is pushing as a product for both cloud computing facilities as well as enterprise data centers.
The announcement coincided with Arista’s analyst day event, and according to one chap who was there, “financials were barely discussed.”
The product uses new chips from Broadcom (AVGO) called “Jericho.”
The move opens a new front in Arista’s battle with Cisco Systems (CSCO), that of routing. Arista has so far contented itself to operate merely in the domain of switches, while Cisco has classically dominated both routing and switching.
Cisco stock is up 51 cents, or 1.5%, at $28.61, while Arista is down 12 cents at $61.77.
Stifel Nicolaus’s Sanjiv Wadhwani, who rates Arista stock a Buy, with a $95 price target, calls this Arista’s entry to the routing market, writing that “the 7500R offers increases in capacity and performance by orders of magnitudes in comparison to the company’s previous highest-capacity spine.”
As a result, “the 7500R supports full internet routing with significant headroom for additional growth in IPv4 and IPv6 routes – broadening the company’s use case.” He thinks that’s a $2 billion new market for the company.
Wadhwani sees a number of applications, including “WAN,” or wide-area routing, “edge,” routing (though “longer-term”), use by content delivery networks (CDN), and also use by the company’s existing cloud computing customers, such as Microsoft (MSFT). The last of these, cloud, is the most immmediate opportunity:
With datacenter core routing (the most immediate opportunity for the company’s new 7500R), Arista looks to collapse the tiers that sit above the spine layer in datacenters today into a single tier via the 7500R. Current datacenter architectures typically use a routing layer to connect the switching fabric (where Arista sits today) with datacenter interconnect (DCI) optical boxes, and/or the Internet. These routers have been purpose built to support internet scale routing and advanced routing protocols – which has led to them being typically expensive proprietary devices that are somewhat inflexible in adapting to changes in application traffic demands and patterns.
Merchant silicon, particularly Broadcom’s Jericho, now has the capacity to support Internet routing – offering internet routing at a much more attractive density and cost. By supporting routing, with Ethernet interfaces and Coherent DWDM optics, we see Arista’s 7500R as a compelling solution for collapsing the DCI and routing layers into what Arista terms the Universal Spine Tier, offering a cost efficient, highly scalable and programmable solution for connecting datacenters to other datacenters and to the Internet.
Gabelli & Co.’s Hendi Susanto reiterates a Buy on Arista, writing that “We are incrementally more positive on Arista Networks” as “the new 7500R Universal Spine has strong routing platform offerings including attractive pricing and best-in-class industry performance, opening a multi-billion dollar market opportunity for the company. We continue to recommend purchase.”
This is going head to head with Cisco, writes Susanto, after attending the announcement at Arista’s headquarters:
7500R Series Universal Spine redefines networking and represents the first inflection point for cloud-scale routing. It provides additional market opportunity of router platform on top of its core switching solutions. It can replace legacy routing solutions and we believe it will compete against legacy router vendors, including Cisco.
Credit Suisse’s Kulbinder Garcha reiterates an Outperform rating, and a $90 price target on Arista, writing that this can replace Cisco’s “Core” routing equipment:
This could be disruptive for several reasons. First, the 7500R is Arista’s first switch & router combination, leveraging the full internet routing table and universal spine, and it is offered as a 100+ Terabit capacity platform in 1/10/25/50/100GbE port options. This means that the traditional core routing layer can now be replaced with an Arista 7500R. Second, fast growing cloud companies are demanding a product like this. For e.g. Netflix, which has already been using a test version, applauds the introduction noting that it is offering breakthrough price/performance at 10x more bandwidth at 1/10th the price of a traditional router. We see this as a first of many wins for Arista.
Nomura U.S. Equity Research’s Jeffrey Kvaal, who has a Buy rating on Arista shares, and a $95 price target, writing that the extent of routing features are a surprise:
While Arista had signaled modest routing features would enter its switch lineup, Arista appears to be aiming higher than thought. The company expects the 7500R to collapse the data center routing layer into the existing spine switching layer, and thus reduce customer spend. Sizeable routing tables should allow Arista to target some of the $9bn service provider edge router market as well.
Note that this will take some time:
While Arista is supporting live routing traffic at present at Netflix, the 7500R will only be broadly available in 2Q and customer certification of the routing features will likely require 6- 12 months. Arista noted collapsing routing and switching into a ‘universal spine’ would be a 3-5 year journey. We expect webscale customers to adopt the 7500R for its 100G switching capabilities rather quickly.
Kvaal sees no immediate hit to Cisco and Juniper Networks (JNPR):
Lengthy certifications aside, existing routing vendors have invested years if not decades in custom code for each telco. Arista would struggle to match that, and so will likely only target telcos who, like AT&T, are shifting architectures. Rivals will have time to gauge customer sentiment and react if needed. Reaction times may be slowed, however, as switches and routing can lie across organizational boundaries and operating systems.
On a less-ebullient note, UBS‘s Steve Milunovich, who has a Neutral rating on Arista, and a $63 price target, writes that the product “embeds some routing features.
Milunovich doesn’t see the product handling the most demanding Internet routing tasks:
Given the routing stack requirements, we believe the 7500R is not addressing the internet-facing router market within data centers. Instead, the target appears to be routers that are used for data center interconnects. Arista did not provide a TAM estimate. In our opinion, the 7500R could capture a portion of the existing $2.2bn DCI market forecast by Dell’Oro. Given switches are priced lower than routers, the true incremental TAM for Arista could be less than $500m. The traditional SP routing market is not a near-term target but architectural changes could open doors over time. We note that Arista has a dedicated service provider sales team.
The announcement coincided with Arista’s analyst day event, and according to one chap who was there, “financials were barely discussed.”
The product uses new chips from Broadcom (AVGO) called “Jericho.”
The move opens a new front in Arista’s battle with Cisco Systems (CSCO), that of routing. Arista has so far contented itself to operate merely in the domain of switches, while Cisco has classically dominated both routing and switching.
Cisco stock is up 51 cents, or 1.5%, at $28.61, while Arista is down 12 cents at $61.77.
Stifel Nicolaus’s Sanjiv Wadhwani, who rates Arista stock a Buy, with a $95 price target, calls this Arista’s entry to the routing market, writing that “the 7500R offers increases in capacity and performance by orders of magnitudes in comparison to the company’s previous highest-capacity spine.”
As a result, “the 7500R supports full internet routing with significant headroom for additional growth in IPv4 and IPv6 routes – broadening the company’s use case.” He thinks that’s a $2 billion new market for the company.
Wadhwani sees a number of applications, including “WAN,” or wide-area routing, “edge,” routing (though “longer-term”), use by content delivery networks (CDN), and also use by the company’s existing cloud computing customers, such as Microsoft (MSFT). The last of these, cloud, is the most immmediate opportunity:
With datacenter core routing (the most immediate opportunity for the company’s new 7500R), Arista looks to collapse the tiers that sit above the spine layer in datacenters today into a single tier via the 7500R. Current datacenter architectures typically use a routing layer to connect the switching fabric (where Arista sits today) with datacenter interconnect (DCI) optical boxes, and/or the Internet. These routers have been purpose built to support internet scale routing and advanced routing protocols – which has led to them being typically expensive proprietary devices that are somewhat inflexible in adapting to changes in application traffic demands and patterns.
Merchant silicon, particularly Broadcom’s Jericho, now has the capacity to support Internet routing – offering internet routing at a much more attractive density and cost. By supporting routing, with Ethernet interfaces and Coherent DWDM optics, we see Arista’s 7500R as a compelling solution for collapsing the DCI and routing layers into what Arista terms the Universal Spine Tier, offering a cost efficient, highly scalable and programmable solution for connecting datacenters to other datacenters and to the Internet.
Gabelli & Co.’s Hendi Susanto reiterates a Buy on Arista, writing that “We are incrementally more positive on Arista Networks” as “the new 7500R Universal Spine has strong routing platform offerings including attractive pricing and best-in-class industry performance, opening a multi-billion dollar market opportunity for the company. We continue to recommend purchase.”
This is going head to head with Cisco, writes Susanto, after attending the announcement at Arista’s headquarters:
7500R Series Universal Spine redefines networking and represents the first inflection point for cloud-scale routing. It provides additional market opportunity of router platform on top of its core switching solutions. It can replace legacy routing solutions and we believe it will compete against legacy router vendors, including Cisco.
Credit Suisse’s Kulbinder Garcha reiterates an Outperform rating, and a $90 price target on Arista, writing that this can replace Cisco’s “Core” routing equipment:
This could be disruptive for several reasons. First, the 7500R is Arista’s first switch & router combination, leveraging the full internet routing table and universal spine, and it is offered as a 100+ Terabit capacity platform in 1/10/25/50/100GbE port options. This means that the traditional core routing layer can now be replaced with an Arista 7500R. Second, fast growing cloud companies are demanding a product like this. For e.g. Netflix, which has already been using a test version, applauds the introduction noting that it is offering breakthrough price/performance at 10x more bandwidth at 1/10th the price of a traditional router. We see this as a first of many wins for Arista.
Nomura U.S. Equity Research’s Jeffrey Kvaal, who has a Buy rating on Arista shares, and a $95 price target, writing that the extent of routing features are a surprise:
While Arista had signaled modest routing features would enter its switch lineup, Arista appears to be aiming higher than thought. The company expects the 7500R to collapse the data center routing layer into the existing spine switching layer, and thus reduce customer spend. Sizeable routing tables should allow Arista to target some of the $9bn service provider edge router market as well.
Note that this will take some time:
While Arista is supporting live routing traffic at present at Netflix, the 7500R will only be broadly available in 2Q and customer certification of the routing features will likely require 6- 12 months. Arista noted collapsing routing and switching into a ‘universal spine’ would be a 3-5 year journey. We expect webscale customers to adopt the 7500R for its 100G switching capabilities rather quickly.
Kvaal sees no immediate hit to Cisco and Juniper Networks (JNPR):
Lengthy certifications aside, existing routing vendors have invested years if not decades in custom code for each telco. Arista would struggle to match that, and so will likely only target telcos who, like AT&T, are shifting architectures. Rivals will have time to gauge customer sentiment and react if needed. Reaction times may be slowed, however, as switches and routing can lie across organizational boundaries and operating systems.
On a less-ebullient note, UBS‘s Steve Milunovich, who has a Neutral rating on Arista, and a $63 price target, writes that the product “embeds some routing features.
Milunovich doesn’t see the product handling the most demanding Internet routing tasks:
Given the routing stack requirements, we believe the 7500R is not addressing the internet-facing router market within data centers. Instead, the target appears to be routers that are used for data center interconnects. Arista did not provide a TAM estimate. In our opinion, the 7500R could capture a portion of the existing $2.2bn DCI market forecast by Dell’Oro. Given switches are priced lower than routers, the true incremental TAM for Arista could be less than $500m. The traditional SP routing market is not a near-term target but architectural changes could open doors over time. We note that Arista has a dedicated service provider sales team.
Wednesday, 2 March 2016
Pass4sure 200-120 Question Answer
Refer to the exhibit.
Exhibit A
After HostA pings HostB, which entry will be in the ARP cache of HostA to support this transmission?
Exhibit B
Exhibit C
Exhibit D
Exhibit E
Exhibit F
Answer: A
Exhibit C
Exhibit D
Exhibit E
Exhibit F
Answer: A
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