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OSI MODEL Question

By robert.hawley ·
I was recently in a discusion about the OSI model and related test questions.
The question that created a such a dillema was this.
What layer of the OSI model does the NIC belong on?
We all know what Cisco says but what do you think, Layer 1 or layer 2?

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L1, hands down...

by ghstinshll In reply to OSI MODEL Question

So if I think it's L1, what does Cisco say "officially"? L1 translates frames into bits for placement on media, it's just that simple. A NCI does this.

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Cisco according to CCNA ref.

by robert.hawley In reply to L1, hands down...

Cisco says the NIC belongs on layer 2 (Data Link Layer) because of the MAC addressing of the card.

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OSI Model

by tohlric In reply to OSI MODEL Question

NICS belong to Layer 2 of the OSI model.

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OSI Layer 2

by robert.hawley In reply to OSI Model

Why do you think they reside on layer 2?

On one hand the NIC convertes frames to bits to pulses of elctricity, this is all layer one functionality, But on the other it also holds the MAC address and strips that portion of the packet off to compare it. This is layer 2 functionality.

The layer two portion is handeled by whatever framing convention that is on the firmware of the card (802.2, 802.3, 802.5 etc).

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Layer 2 is correct.

by ecjones In reply to OSI Layer 2

The MAC address says it all, this is a layer to function.

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Top down.

by madroxxx In reply to OSI Layer 2

You have to place a decive on the top layer it operates and it is assumed that it also uses the layers below it. For example a router is a layer 3 device but also operates on layer 2,1. A network card broadcasts data to MAC addy's and therefore is layer 2. Of course it operates on layer 1 as well.

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Following that logic

by robert.hawley In reply to Top down.

Well following that logic routers are application then, because they use TFTP. That is the highest protocol they use.

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That's a stretch.

by madroxxx In reply to Following that logic

While a Router does use TFTP for it's own updates that is not it's purpose. It's purpose is to route. This happens at layer 3. A network cards purpose is to transfer data to another device, this happens at layer 2&1.

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by Jellimonsta In reply to That's a stretch.

Like I said... "true"! P

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by robert.hawley In reply to That's a stretch.

But the purpose of a NIC card is to trasmit data via pullses of electricty doen the cable, the firmware and drivers (both software) handeling the framming.

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