In this section, you're going to be reintroduced to a networking model you first saw in your CCNA studies. No, it's not the OSI model or the TCP/IP model - it's the Cisco Three-Layer Hierarchical Model. Let's face it, just about all you had to do for the CCNA was memorize the three layers and the order they were found in that model, but the stakes are raised here in your CCNP studies. You need to know what each layer does, and what each layer should not be doing. This is vital information for your real-world network career as well, so let's get started with a review of the Cisco three-layer model, and then we'll take a look at each layer's tasks. Most of the considerations at each layer are common sense, but we'll go over them anyway!
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Today we'll take a look at the core layer of the Cisco model.
Before making a major investment into a computer certification, consider the steps that a vendor does or does not make to protect your investment. Computer certifications have helped me tremendously in building my IT career. By asking the right questions, and taking a hard look at your motives and plans before pursuing a given certification, they can do the same for you. Chris Bryant, 12933, is the owner of The Bryant Advantage ( //www.thebryantadvantage.com), home of free CCNA and CCNP tutorials, The Ultimate CCNA Study Package, Ultimate CCNP Study Packages, and CCNA CBT video training. Pass the CCNA exam, BSCI exam, and BCMSN exam with Chris Bryant, 12933!
Thinkpad The term core switches refers to any switches found here. Switches at the core layer allow switches at the distribution layer to communicate, and this is more than a full-time job. It's vital to keep any extra workload off the core switches, and allow them to do what they need to do - switch! The core layer is the backbone of your entire network, so we're interested in high-speed data transfer and very low latency - that's it!
Interesting traffic brings the link up; by default, any traffic can cross the link once it's up; a lack of interesting traffic is what brings the link down. In Part II of this tutorial, we'll take a look at some common scenarios that make the ISDN link stay up, and what can be done about it. Chris Bryant, 12933, is the owner of The Bryant Advantage ( //www.thebryantadvantage.com), home of free CCNA and CCNP tutorials, The Ultimate CCNA Study Package, Ultimate CCNP Study Packages, and CCNA CBT video training. Pass the CCNA exam, BSCI exam, and BCMSN exam with Chris Bryant, 12933!
Microsoft Core layer switches are usually the most powerful in your network, capable of higher throughput than any other switches in the network. Remember, everything we do on a Cisco router or switch has a cost in CPU or memory, so we're going to leave most frame manipulation and filtering to other layers. The exception is Cisco QoS, or Quality of Service. QoS is generally performed at the core layer. We'll go into much more detail regarding QoS in another tutorial, but for now, know that QoS is basically high-speed queuing where special consideration can be given to certain data in certain queues. (You'll soon find that this is a very basic definition!)
Today we'll take a look at the core layer of the Cisco model. The term core switches refers to any switches found here. Switches at the core layer allow switches at the distribution layer to communicate, time job. It's vital to keep any extra workload off the core switches, switch! The core layer is the backbone of your entire network, so we' that's it!
Laptop Computers We always want redundancy, but you want a lot of redundancy in your core layer. This is the nerve center of your entire network, so fault tolerance needs to be as high as you can possibly get it. Root bridges should also be located in the core layer.
The Cisco Catalyst 6000 family brings data, voice, and video integration onto a single platform for fully integrated communications in the access, distribution, and core layers of the network.
Laptop Computer The importance of keeping unnecessary workload off your core switches cannot be overstated. In the next part of this BCMSN tutorial, we'll take a look at how the other layers of the Cisco three-part model do just that.
The importance of keeping unnecessary workload off your core switches cannot be overstated. In the next part of this BCMSN tutorial, we' part model do just that.
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Notebooks Chris Bryant, CCIE #12933, is the owner of The Bryant Advantage (http://www.thebryantadvantage.com), home of free CCNA and CCNP tutorials, The Ultimate CCNA Study Package, Ultimate CCNP Study Packages, and CCNA CBT video training. Pass the CCNA exam ,BSCI exam , and BCMSN exam with Chris Bryant, CCIE #12933!
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