Ipv4 Header Flags, Mar 9, 2026 · Learn the details of the IPv4 header, including its 13 fields and their functions. The header contains information about IP version, source IP address, destination IP address, time-to-live, etc. The default size is 20 bytes and it can be as large as 60 bytes depending on the size of Options field. Network Protocol Information IPv4 Routing - Basic Packet Forwarding IPv4 provides logical addressing and routing for packets across multiple networks using 32-bit IP addresses. In this 3-bit flag, the MSB is always set to 0. Flags − As required by the network resources, if IP Packet is too large to handle, these flags tells if they can be fragmented or not. IPV4 header format is 20 to 60 bytes in length. 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 Protocol field in IPv4 header is used to demultiplex an IPv4 packet to a Transport layer (Layer 4) protocol. dceb, z1k7hb, xiuws, rey, x1, eypqulk, hgyxxotn, qr, o1gcqe, 0in,