What is CRC and how does it works?

What is CRC and how does it works?

CRC errors refer to Layer 1 or 2 issues.

Two things you should check :

1. Both the ends of the interfaces have some speed and duplex
settings.

2. Check the physical cabling or copper line.

CRC (Cyclic Redundancy Check) is apolynomial function  on the frame
which returns a 4B number in Ethernet Frames.

It will catch all single bit errors and a good percentage of double
bit errors. It is thus meant to ensure that the frame was not corrupted in
transit.

The CRC is an error detectionalgorithms and is designed to maximize the probability of detecting
errors using only a small number of redundant bits. The CRC-32 gives strong
protection against common bit errors in messages that are thousands of bytes
long. If you want to know more about how does it works, I recommend a book
called <Computer Networks - A systems approach>. The CRC algorithm is
discussed around page 92 through 102.

来自为知笔记(Wiz)