Read RFC 1071 and RFC 1624 to see how IP checksum is computed. Then practice with the following trivial blocks of words by hand:  0x36f7 0xf670 0x2148 0x8912 0x2345  0x7863 0x0076  What if the first...

Read RFC 1071 and RFC 1624 to see how IP checksum is computed. Then practice with the following trivial blocks of words by hand:

 0x36f7 0xf670 0x2148 0x8912 0x2345

 0x7863 0x0076

 What if the first word above is changed to 0x36f6?

RFCs are available at http://www.ietf.org/rfc.html.

Why is the destination address field usually located in the head of a frame, and the FCS field located in the tail of a frame?