Getting Started with IP protocols

Crossing, please give me more advice.

IP protocol, Interner Protocol, Internet Protocol, provides three-layer addressing and three-layer communication capabilities.

Grab the package as follows:

Summary of content:

Content analysis:
1, Version: Used to identify the IP protocol version number, Ipv4/ipv6
2, the first length (headers length): Identifies the length of the IP header, the minimum length is 20 bytes, the maximum length is 60 bytes;
3. Service type (Differentiated Services Field): DHCP, which performs QoS functions to classify service categories and prioritize services.
--Minimize delay #最小延迟
0100--Maximize throughput #最大吞吐量
0010--Maximize reliability #最高可靠性
0001--Minimize monetary cost #最小费用
0000--Normal service #一般服务
4, total length: The total length of the IP packet, the maximum length is 65,535 bytes;
5, identification (identification): 16 bits, for the Shard Reload
6, Flag (Flags): RB+DF+MF Total 3 people

RB This bit doesn't matter, ignore.
Df:don ' t fragment, do not Shard, df=1 is not Shard, and vice versa.
Mf:more fragment, more shards, mf=1 that the slice is not the last piece of the packet, can still be fragmented, and vice versa.
7, chip offset (Fragment offset): 13 bits, in the reload of the data required to provide the field offset
8. TTL lifetime (Time to Live): Default maximum ttl=255, after a router lifetime-1, anti-ring
9, Protocol number (PROTOCOL), used to identify the upper application
10, head Check and (header Checksum): To achieve data integrity check, parity algorithm
11+12, source IP address: Used to identify recipients and senders

Getting Started with IP protocols