Frames?

Do we need to know how many bytes in each part of a frame? Or that the max size is 1500 and that you can fragment it?

PM shows
DLC Header 14 bytes
IP Header 20 bytes
TCP Header 20 bytes
TCP Data 1460 bytes
FCS 4 bytes
Do I need to know these numbers?

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Comments

stryder144

I am not sure that the Network+ exam goes into that depth but it might be worth noting the following:

Preamble and frame delimiter (not part of the frame) - 8 bytes
MAC address for destination - 6 bytes
MAC address for source - 6 bytes
802.1Q VLAN tag (optional) - 4 bytes
EtherType/802.3 Length - 2 bytes
Payload (data) - 42 to 1500 bytes
Frame Check Sequence - 4 bytes

Minimum frame length - 64 bytes
Maximum frame length - 1522 bytes

As such, I would know the minimum and maximum length and that frames have headers and trailers added to the Layer 3 packet (which is the data payload of the frame).

Jon_Cisco

Disclaimer! I have not taken the Net+ exam.

However my experience is the fine details like that are not over emphasized on the test. It's more important to understand the structure of a frame and how the data is used by the system.

Lunchbocks

I think the biggest thing to know is that frames are layer 2 PDUs, and that routers use frames on the wire for destination devices (not to be confused with routers using packets to deliver the data to the end destination).