1.1.e [ii] MSS
- TCP MSS operates at Layer 4. It is 40 bytes lower than the IP MTU as it does not take headers in to consideration (20 byte IP and 20 byte TCP).
- IP MTU operates at Layer 3. It is the maximum size a packet can be before it needs to be fragmented (or dropped if the df-bit is set).
- Ethernet MTU (Layer 2) – 1500 bytes, excluding the header and trailer.