# IPv4: [Internet Protocol](https://app.gitbook.com/@mudassirs46/s/network-fundamentals/~/drafts/-MRZ8l67L5MHnaQIEh9W/ip-internet-protocol) Version 4 is a L3 Network Protocol of 4 Bytes 32 bits Decimal Address which can produce over 4 Billion (4,294,967,296) Unique Addresses. * This 32-bit IPv4 Address is divided into 4 parts called Octets (each of 1 byte/8 bit) * Those bits in each Octet are represented by a number. Starting from the left they have a value of 128, 64, 32, 16, 8, 4, 2, 1. * Each bit on the octet can be either 1 or 0. If a Number is 1 then that octet is counted if it is a 0 then it is ignored. * Just by manipulating 1s & 0s in each octet, we get a range from 0-255. * **IPv4 Header:** * It is a connectionless Protocol that offers only best-effort delivery. * Each packet is treated differently hence packets may take different paths based on options like Hop Count, Load Balancing, or Bandwidth offered by different Routing Protocols. * IP has no Data Recovery, No built-in Sessions & No Re-transmission features. Hence, L3 Internet Protocol relies on the L4 TCP which offers all these features & provides guaranteed delivery of Data & packets. * Routers route packets based on NID & not HID. * IPv4 Address is divided into [2 parts](https://app.gitbook.com/@mudassirs46/s/network-fundamentals/~/drafts/-MRZ8l67L5MHnaQIEh9W/ipv4-address-parts): * Network Port (NID) * Host Portion (HID) * IPv4 Classfull Addresses were divided into 5 [Classes](https://app.gitbook.com/@mudassirs46/s/network-fundamentals/~/drafts/-MRZ8l67L5MHnaQIEh9W/ipv4-address-classes-1) ## Reference: * * CCNA 200-301 OCG, Volume 1, Pg. 74 - Wendell Odom . --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://mudassirs46.gitbook.io/network-fundamentals/ipv4.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.