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Home > Archive > CCNA > July 2001 > Cisco layers
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| mike99 2001-07-24, 10:30 am |
| Hey gang,
I'm writing my exam tomorrow (July 26). I went through Cybex and Cisco book.
I'm still  when it comes to choose which router/switch model goes on Access, Distribution or Core layer...
In other words, should I know if catalyst switch models 2926G,5000,6500,8500 go on access layer or distrib layer ? You think there might be questions like that in the exam ?
...Mike | |
| Silkysmoothe1 2001-07-24, 4:28 pm |
| I realize your concern,,,No, they shouldn't ask you anything about series of routers however, some questions may be worded like,
A) The cisco 1900-series router will/is bla bla bla,,,,config question,,etc, or cli-question.
You will need to know you DOD model,,,I had only one question over it, go figure.
"In other words, should I know if catalyst switch models 2926G,5000,6500,8500 go on access layer or distrib layer ? You think there might be questions like that in the exam ?" NO, I had no questions of the sort,
,,,good luck,,,,
silky | |
| lennon57 2001-07-24, 4:44 pm |
| I see your definately 'Hard Core' into the Lammle book.
I dont know why they would ask Model Numbers on the CCNA test. You are not being tested for the sales arena.
Know the basics on configuration of switches vs routers.
I, like silky, didn't have any questions relaying one model to another, and where they fit in the Cisco model.
It is good reference material though. I suspect you would want to use it in a design aspect. | |
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| I believed they only ask 1900 and 5000! | |
| strikeattack 2001-07-24, 6:50 pm |
| I am currently studying for this BCMSN test. I am amazed so far as to how simple the material is so far. And yes, I am reading Cisco Press BCMSN. I am posting the information from my notes regarding the Hierarchial model. I believe this is probably sufficient for passing the test.
THE HIERARCHIAL MODEL:
Over the years, a distinct model has taken shape in the campus network. This model is called the hierarchial model.
1. Access Layer; the access layer of the network is the point in which end users are allowed into the network. This layer can provide further tuning such as access lists or packet filtering. However, the key function of this layer is to provide end-user access to the network. Typically 10BaseT Ethernet. EX: Catalyst 1900, 2820, 2900, 4000, or 5000.
2. Distribution Layer; the distribution layer marks the point between the access and core layers of the network. End-user switches typically do not plug directly into the core switches, so for scalability reasons, the distribution layer is added. Some functions are: VLAN aggregation, workgroup access, broadcast or multicast domain boundaries, Inter-VLAN routing, media translations, or security. Typically 100BaseT Fast Ethernet. EX: Catalyst 5000 or 6000.
3. Core (backbone) Layer; The primary purpose of the core layer is to switch traffic as fast as possible. This layer of the network should not involve packet manipulation or any processing that slows down traffic switching. Access lists and packet filtering should be avoided in the core. The core layer is responsible for providing inter-workgroup connectivity and switching packets as fast as possible. A core is required if there are two or more switch blocks. The core block is responsible for transferring cross-campus traffic. Cisco recommends that a minimum of two devices be present in the core to provide redundancy (do this by providing redundant links to each switch block and letting SPT handle the redundant links). Typically Interconnected by 1000BaseT Gigabit Ethernet. EX: Catalyst 6500 or 8500.
a. Collapsed Core; a core in which the distribution layer and core layer functions are performed within the same device. This is typically used in smaller campus networks. Each access layer switch has a redundant link to the distribution layer/core layer switch.
b. Dual Core; a core which is necessary when two or more switch blocks exist and redundant connections are required.
Hope this helps! | |
| mike99 2001-07-25, 6:47 am |
| Thanks. | |
| Silkysmoothe1 2001-07-25, 9:13 am |
| you just barely beet me to the punch. I couldn't have said it better myself,, hey,I guess this means, if we were in a boxing match, you would have knocked me clean out,??????????
LOL,,,
,,,silky,,, | |
| strikeattack 2001-07-25, 4:48 pm |
| SilkySmoothe,
You are a sad, strange little man. I don't always understand your posts, but I always enjoy reading them.
 | |
| Silkysmoothe1 2001-07-25, 4:58 pm |
| quote:
Originally posted by strikeattack
SilkySmoothe,
You are a sad, strange little man. I don't always understand your posts, but I always enjoy reading them.
Your pretty close, I am sad "sometimes, not all" and strange, well I do have a twisted sense of humor but that is my dark side and we all have a dark side. What's funny to me is normally not funny to anyone else but a few. and being little,,,well I'm 6'2 and 195lbs,,,and well, quite frankly most of my girlfriends could argue on my behalf.
LOL,,
Just trying to find a laugh,,,,seriously kidding. I'm glad you enjoy reading my post,,that's part of the game.
,,always,,,silky,,, | |
| depamo 2001-07-29, 10:48 am |
| The Hierarchial Model wasn't designed to tell you exactly which systems to use at each layer, it just describes what is occuring at each layer and insures the scalabilithy of the design.
Naturally the need to do certain tasks expected at certain layers would warrant the use of higher performance or systems with different capabilities.
An example of this is a Frame Relay core for a large company that is passing in excess of 50Mb/s or a combination of traffic types then back to a smaller company that uses FDDI in the core accessing it with 4k routers. There are many differences in what goes where but that is not defined in the Hierarchial Model.
Some things that do determine the type of router or device to go where is more placed on the type of LAN or WAN type it is terminating, the amount of traffic and IOS applications being used.
Good luck on your exam! |
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