Ipv4 Header format ; Specifications | IT Officer Lecture IBPS and SBI Video Lecture | Crash Course for SSC CGL (Hindi)

Ans. The format of the IPv4 header consists of several fields including the version, header length, type of service, total length, identification, flags, fragment offset, time to live, protocol, header checksum, source IP address, and destination IP address.

Ans. The specifications of the IPv4 header include the following: - Version: It indicates the IP protocol version being used, which is typically IPv4. - Header Length: It specifies the length of the header in 32-bit words. - Type of Service: It defines the quality of service requested by the sender. - Total Length: It specifies the total length of the IPv4 datagram, including both header and data. - Identification: It helps in identifying fragments of a single IP datagram. - Flags: It is used for fragmentation and reassembly of IP datagrams. - Fragment Offset: It indicates the position of a fragment in the original IP datagram. - Time to Live: It determines the maximum number of hops an IP packet can take before being discarded. - Protocol: It identifies the protocol used in the data portion of the IP datagram. - Header Checksum: It is used to verify the integrity of the IPv4 header. - Source IP Address: It represents the IP address of the sender. - Destination IP Address: It represents the IP address of the intended recipient.

Ans. The IPv4 header includes a field called "Header Checksum" which is used to ensure the integrity of the data. The checksum is calculated based on the contents of the header and is used to detect any errors that may have occurred during transmission. If the checksum calculated at the destination does not match the checksum sent by the sender, it indicates that the data may have been corrupted and the packet is discarded.

Ans. The Time to Live (TTL) field in the IPv4 header serves the purpose of limiting the lifespan of an IP packet. It is represented by a numerical value that determines the maximum number of hops (routers) the packet can traverse before being discarded. Each time the packet passes through a router, the TTL value is decremented by one. If the TTL value reaches zero, the router discards the packet and sends an ICMP Time Exceeded message back to the sender.

Ans. The IPv4 header handles packet fragmentation through the use of the Flags and Fragment Offset fields. When a router receives an IP packet that exceeds the Maximum Transmission Unit (MTU) of the outgoing interface, it fragments the packet into smaller fragments. The Flags field is used to indicate whether a packet is fragmented or not, and the Fragment Offset field specifies the position of each fragment within the original packet. The destination host then reassembles the fragments based on the Fragment Offset field to reconstruct the original IP packet.