IP Datagram Structure

6 Questions

To indicate the length of the IP header

To reassemble fragmented packets

Limits the packet's lifespan to prevent indefinite circulation

To indicate the higher-level protocol encapsulated in the datagram

To ensure the integrity of the header during transmission

To enable additional features, such as security or routing

Study Notes

The IP datagram consists of 14 key parts.
Version specifies the IP version used, either IPv4 or IPv6.
Header Length indicates the length of the IP header, which is essential for determining where the data starts.

Type of Service (ToS) provides Quality of Service (QoS) information, indicating how the packet should be handled, such as prioritizing speed or reliability.
Total Length specifies the entire length of the datagram, including both header and data.
Identification is a unique identifier used for reassembling fragmented packets.
Flags control or indicate if the packet can be fragmented and whether more fragments follow.
Fragment Offset indicates where in the overall message this fragment belongs.

Time to Live (TTL) limits the packet's lifespan to prevent it from circulating indefinitely, decrementing at each hop and being discarded if it reaches zero.
Protocol indicates the higher-level protocol encapsulated in the datagram, such as TCP or UDP.
Header Checksum provides error-checking for the header, ensuring its integrity during transmission.

Source IP Address is the IP address of the sender.
Destination IP Address is the IP address of the recipient.
Options are optional settings for additional features, such as security or routing.

Payload is the actual data being transported, including the segment from the transport layer.
The components of the IP datagram ensure that it can be routed, verified for integrity, and properly delivered across networks.