Wireshark Lab: IP v8.0
Here is the IP address: 192.168.1.102
Within the "upper layer protocol field" preceding the IP packet header, it is indicated as 17. So let's talk about User Datagram Protocol (UDP) - a protocol commonly used in connectionless communication.
The packet examines the IP header as a 20-byte extension. It identifies this in the "Header Length" field of the IP header, where it corresponds to a length indicator of 5 (multiplied by 4). The payload of the IP datagram refers to the meaningful data it carries. In this case, the IP payload length is calculated by subtracting the IP header length from the total length of the IP datagram.
The persistence of discontinuities remains a constant issue in IP datagrams. It is worth noting that the "Flags" field in the IP header remains unchanged, specifically the "Don't Fragment" bit.
The host computer must include certain mutable IP fields in a series of ICMP packets that have been sent. These fields include the Source Address, Identification, Time to Live (TTL) Checksum, and Sequence Number.
These are the constant parts of the header: Version, Header Length, Differentiated Services Codepoint (DSCP), Explicit Congestion Notification (ECN), Total Length, Flags, Fragment Offset, Protocol, and Destination Address. Such determination is crucial, as it guarantees precise and accurate communication, especially when dealing with the persistence of routing.
The destination Port field of the IP packet shows a consistent pattern where the numbers increase by 1 with each subsequent packet. For instance, one can consider the initial identification numbers as 13014 and subsequent numbers in sequence, such as 13015 and beyond.
The value that holds significance is 768 for the TTLf, along with a value of 1 for the ICMP TTL-exceeded replies from the closest router, which are then relayed to the computer.
Indeed, these values never change on any ICMP TTL-exceeded reply, which is crucial for accurate error interpretation and network repairability.
IP fragmentation occurs when the implementation includes an ICMP Echo Request message with a packet size adjustment of 2000 bytes in Pingplotter.
Packet number 92 introduces the creation of a disjointed IP data packet, consisting of two fields: the Fragment Offset (coded as 0) and the absence of More Fragments, indicating the first and last fragments.
On the other hand, packet number 93 provides further insight into subsequent fragmented occurrences. This is highlighted by the presence of the More Fragments flag and a Fragment Offset field set at 1480, suggesting a sequential fragmentation process.
The shift from the first to the second fragment highlights changes primarily seen in the "More Fragments" flag and the "Fragment Offset" field.
When the Packet Size in pingplotter is adjusted to 3500 bytes, the original datagram gets fragmented into a total of 14 fragments.
Notable changes can be observed in the "Fragment Offset" and "Time to Live" (TTL) fields, which indicate the fragmented nature and routing details of the datagram.