$$a$)$ Data link protocols almost always put the CRC in a trailer rather than in a header, Why? A bit$$

$$stream $10011101$ is transmitted using the standard CRC method. The generator polynomial is x$3+1$

$.$Show that the actual bit string transmitted. Suppose the third bit from the left is inverted$$

$$during transmission. Show that this error is detected at the receiver$$s end.

$$b$)$ Capture ICMP packets in wireshark and analyze in detail.