in data link layer header there is field of #Trailer which work as a guard and check the data correction Question is that is any field in Layer#3 which work is same like this or what different between Trader (in Layer#2) and Header Checksum(in Layer#3)
1 Answer
For data link layers (the 2 most common being 802.3 and 802.11), the FCS will detect single bit errors anywhere in the entire frame.
The header checksum in an IP packet only detects errors in the header. There is no trailing checksum in IP. It's up to the upper layers to detect errors in the payload.