What is in the header of an IP packet?
Each IP packet contains both a header (20 or 24 bytes long) and data (variable length). The header includes the IP addresses of the source and destination, plus other fields that help to route the packet. The data is the actual content, such as a string of letters or part of a webpage.
What are the different types of options available in the IPv4 packet?
IPv4 uses 32-bit addresses for Ethernet communication in five classes: A, B, C, D and E. Classes A, B and C have a different bit length for addressing the network host.
What does an IP header look like?
From a packet filtering point of view, the IP header contains four interesting pieces of information: The IP source address – four bytes long, and typically written as something like 172.16. 244.34. The IP destination address – just like the IP source address.
What is the minimum header size of an IP packet?
20 bytes
The minimum size is 20 bytes (header without data) and the maximum is 65,535 bytes. All hosts are required to be able to reassemble datagrams of size up to 576 bytes, but most modern hosts handle much larger packets.
What is header length in IP header?
Header Length—Technically, this is the Internet header length (IHL). It is the length of the IP header in 4-byte (32-bit) units known as “words,” and includes any option fields present and padding needed to align the header on a 32-bit boundary. In Figure 7.2, this is 20 bytes, which is most common.
What are IP options?
IP Options provide a way to introduce special-handling services to the datagrams or packets, allowing a system to instruct a router to send the datagram through a predefined network, or to note that the path a datagram took should be recorded, among other things.
What is a packet header?
A packet header is the portion of an IP (Internet protocol) packet that precedes its body and contains addressing and other data that is required for it to reach its intended destination. Regardless of their size, each packet consists of three main parts: a header, the body, also called the payload, and a trailer.
What is maximum header size of IP packets?
The maximum length of an IP header is 24 bytes, or six 32-bit increments. Therefore, the header length field should contain either 5 or 6.
What is the minimum header size of an IP packet 16 bytes 10 bytes 20 bytes 32 bytes?
This 16-bit field defines the entire packet size in bytes, including header and data. The minimum size is 20 bytes (header without data) and the maximum is 65,535 bytes.
How many 32 bit words are in an IP header?
It is the length of the IP header in 4-byte (32-bit) units known as “words,” and includes any option fields present and padding needed to align the header on a 32-bit boundary. In Figure 7.2, this is 20 bytes, which is most common.
What is SSR and LSR?
The following two options are discouraged because they create security concerns: Loose Source and Record Route (LSRR) and Strict Source and Record Route (SSRR). Many routers block packets containing these options.
What is options field in IPv4 header?
The IPv4 header is variable in size due to the optional 14th field (options). The IHL field contains the size of the IPv4 header, it has 4 bits that specify the number of 32-bit words in the header. The minimum value for this field is 5, which indicates a length of 5 × 32 bits = 160 bits = 20 bytes.
What is in the header of a packet?
A packet header is the portion of an IP (Internet protocol) packet that precedes its body and contains addressing and other data that is required for it to reach its intended destination.
Why is there a padding in IP packet?
This field has a size limit of 46 bytes (minimum) to 1500 bytes (maximum). Due to this limit, the network (upper) layer can’t pack more or less data in a single packet (encapsulated data of the upper layer). If data is less than the minimum requirement, padding is added. If data is more than the maximum limit, extra data is packed in the next packet.
What is an IPv4 packet header?
Internet Protocol Version 4- IPv4 short for Internet Protocol Version 4 is the fourth version of the Internet Protocol (IP). IP is responsible to deliver data packets from the source host to the destination host. This delivery is solely based on the IP Addresses in the packet headers. IPv4 is the first major version of IP.
What is the minimum size of the IPv6 packet header?
The IPv6 packet header has a minimum size of 40 octets. Options are implemented as extensions. This provides the opportunity to extend the protocol in the future without affecting the core packet structure.