Fragments keep the same identification and endpoints while lengths and offsets differ.

highlighted = computed this step

Fragments share an identification

Both fragment headers carry identification 0x1c46.

identification=0x1c46\text{identification}=0x1c46
Same packet identityThe two toy IPv4 fragment headers are decoded from exact bytes.Fragment 1 header160 bits / 20 bytes0x450000241c4620004006d1feac100a63ac100a0cbyte 0byte 1byte 2byte 301000101000000000000000000100100byte 4byte 5byte 6byte 700011100010001100010000000000000byte 8byte 9byte 10byte 1101000000000001101101000111111110byte 12byte 13byte 14byte 1510101100000100000000101001100011byte 16byte 17byte 18byte 1910101100000100000000101000001100version4ihl5dscp-ecn0x00total-length36identification0x1c46fragment-offset0ttl64protocol6->TCPheader-checksum0xd1fesource172.16.10.99destination172.16.10.12reserved: clear df: clear mf: setFragment 2 header160 bits / 20 bytes0x4500001c1c4600024006f204ac100a63ac100a0cbyte 0byte 1byte 2byte 301000101000000000000000000011100byte 4byte 5byte 6byte 700011100010001100000000000000010byte 8byte 9byte 10byte 1101000000000001101111001000000100byte 12byte 13byte 14byte 1510101100000100000000101001100011byte 16byte 17byte 18byte 1910101100000100000000101000001100version4ihl5dscp-ecn0x00total-length28identification0x1c46fragment-offset2ttl64protocol6->TCPheader-checksum0xf204source172.16.10.99destination172.16.10.12reserved: clear df: clear mf: clear

Addresses also stay together

Both headers keep the same source and destination fields. The bit strips decode those exact address bytes.

protocol=6\text{protocol}=6
Same packet identityThe two toy IPv4 fragment headers are decoded from exact bytes.Fragment 1 header160 bits / 20 bytes0x450000241c4620004006d1feac100a63ac100a0cbyte 0byte 1byte 2byte 301000101000000000000000000100100byte 4byte 5byte 6byte 700011100010001100010000000000000byte 8byte 9byte 10byte 1101000000000001101101000111111110byte 12byte 13byte 14byte 1510101100000100000000101001100011byte 16byte 17byte 18byte 1910101100000100000000101000001100version4ihl5dscp-ecn0x00total-length36identification0x1c46fragment-offset0ttl64protocol6->TCPheader-checksum0xd1fesource172.16.10.99destination172.16.10.12reserved: clear df: clear mf: setFragment 2 header160 bits / 20 bytes0x4500001c1c4600024006f204ac100a63ac100a0cbyte 0byte 1byte 2byte 301000101000000000000000000011100byte 4byte 5byte 6byte 700011100010001100000000000000010byte 8byte 9byte 10byte 1101000000000001101111001000000100byte 12byte 13byte 14byte 1510101100000100000000101001100011byte 16byte 17byte 18byte 1910101100000100000000101000001100version4ihl5dscp-ecn0x00total-length28identification0x1c46fragment-offset2ttl64protocol6->TCPheader-checksum0xf204source172.16.10.99destination172.16.10.12reserved: clear df: clear mf: clear

Each fragment has its own total length

The first fragment total length is 36; the second fragment total length is 28.

36,2836,28
Same packet identityThe two toy IPv4 fragment headers are decoded from exact bytes.Fragment 1 header160 bits / 20 bytes0x450000241c4620004006d1feac100a63ac100a0cbyte 0byte 1byte 2byte 301000101000000000000000000100100byte 4byte 5byte 6byte 700011100010001100010000000000000byte 8byte 9byte 10byte 1101000000000001101101000111111110byte 12byte 13byte 14byte 1510101100000100000000101001100011byte 16byte 17byte 18byte 1910101100000100000000101000001100version4ihl5dscp-ecn0x00total-length36identification0x1c46fragment-offset0ttl64protocol6->TCPheader-checksum0xd1fesource172.16.10.99destination172.16.10.12reserved: clear df: clear mf: setFragment 2 header160 bits / 20 bytes0x4500001c1c4600024006f204ac100a63ac100a0cbyte 0byte 1byte 2byte 301000101000000000000000000011100byte 4byte 5byte 6byte 700011100010001100000000000000010byte 8byte 9byte 10byte 1101000000000001101111001000000100byte 12byte 13byte 14byte 1510101100000100000000101001100011byte 16byte 17byte 18byte 1910101100000100000000101000001100version4ihl5dscp-ecn0x00total-length28identification0x1c46fragment-offset2ttl64protocol6->TCPheader-checksum0xf204source172.16.10.99destination172.16.10.12reserved: clear df: clear mf: clear

Summary

The identification and endpoints tie these two smaller headers back to the same toy packet.

id=0x1c46\text{id}=0x1c46
Same packet identityThe two toy IPv4 fragment headers are decoded from exact bytes.Fragment 1 header160 bits / 20 bytes0x450000241c4620004006d1feac100a63ac100a0cbyte 0byte 1byte 2byte 301000101000000000000000000100100byte 4byte 5byte 6byte 700011100010001100010000000000000byte 8byte 9byte 10byte 1101000000000001101101000111111110byte 12byte 13byte 14byte 1510101100000100000000101001100011byte 16byte 17byte 18byte 1910101100000100000000101000001100version4ihl5dscp-ecn0x00total-length36identification0x1c46fragment-offset0ttl64protocol6->TCPheader-checksum0xd1fesource172.16.10.99destination172.16.10.12reserved: clear df: clear mf: setFragment 2 header160 bits / 20 bytes0x4500001c1c4600024006f204ac100a63ac100a0cbyte 0byte 1byte 2byte 301000101000000000000000000011100byte 4byte 5byte 6byte 700011100010001100000000000000010byte 8byte 9byte 10byte 1101000000000001101111001000000100byte 12byte 13byte 14byte 1510101100000100000000101001100011byte 16byte 17byte 18byte 1910101100000100000000101000001100version4ihl5dscp-ecn0x00total-length28identification0x1c46fragment-offset2ttl64protocol6->TCPheader-checksum0xf204source172.16.10.99destination172.16.10.12reserved: clear df: clear mf: clear