Does the MTU of a TCP packet include the TCP & IPv4 headers?

Question

Or: What is the maximum payload size for a TCP/IPv4 packet.

Much appreciated!

Cheers.

Answer 1

The MTU of an IP packet is the entire packet, including all IP and higher level headers (such as TCP headers) and payload. Lower level headers (such as Ethernet frames) are not included since they're not IP's concern. However the actual MTU value is influenced by the lower levels, as there's usually a limit, and IP has to stick to it.

Answer 2

MTU = IP Header + Tcp Segment

MSS = Data(doesn't include TCP header)