Internet Protocol Version 4 (IPv4) ================================== .. toctree:: :maxdepth: 1 :hidden: :includehidden: IPv4/ipv4 IPv4/IPv4_Header_Structure IPv4/IPv4_Packet_Routing IPv4/IPv4_Fragmentation IPv4/IPv4_Connectionless_Protocol IPv4/IPv4_Protocol_Identification IPv4/IPv4_Time_to_Live IPv4/IPv4_Addressing_Anycast_Addressing IPv4/IPv4_Addressing_Broadcast_Addressing IPv4/IPv4_Addressing_CIDR IPv4/IPv4_Addressing_Classful_Addressing IPv4/IPv4_Addressing_Multicast_Addressing IPv4/IPv4_Addressing_NAT IPv4/IPv4_Addressing_Subnetting IPv4/IPv4_Addressing_Unicast_Addressing IPv4/EGP IPv4/IS_IS IPv4/MP_BGP IPv4/OSPF IPv4/RIPv1 IPv4/RIPv2 IPv4 is the foundational Layer 3 protocol of the TCP/IP stack, responsible for logical addressing, routing, and packet delivery across networks. Although its address space is limited, it remains widely deployed across global networks. .. list-table:: :widths: 20 60 20 :header-rows: 1 * - Category - Description - Use Case * - IPv4 Basics - Covers the core format, header structure, and key attributes of IPv4. *32-bit address space, connectionless operation, TTL, fragmentation.* - LAN/WAN connectivity, internet communication * - IPv4 Header Structure - Explains the layout and fields of the IPv4 packet header. *Includes version, header length, total length, protocol, source/destination IPs.* - Packet parsing, firewall rules, network diagnostics * - IPv4 Packet Routing - Covers how IPv4 packets are forwarded across networks using routing tables. *Path selection based on destination IP and next-hop logic.* - Internet communication, multi-network environments, router configuration * - IPv4 Fragmentation - Describes how large IPv4 packets are split into smaller fragments to traverse networks with lower MTUs. *Includes identification, flags, fragment offset.* - Transmission over heterogeneous networks, avoiding packet drops due to MTU limits * - IPv4 Connectionless Protocol - Explains that IPv4 is a connectionless protocol, meaning packets are routed independently without session state. *Each datagram is treated separately.* - Stateless communication, DNS queries, video streaming, VoIP * - IPv4 Protocol Identification - Details the Protocol field in the IPv4 header that specifies the upper-layer protocol (e.g., TCP, UDP, ICMP). *Enables correct payload handling at the destination.* - Packet demultiplexing, firewall filtering, protocol-specific handling * - IPv4 Time to Live (TTL) - Describes the TTL field in the IPv4 header which limits the lifespan of packets to prevent infinite looping. *Decremented at each router hop.* - Loop prevention, traceroute, path diagnostics * - IPv4 Addressing - How IPv4 addresses are structured, assigned, and translated. *Unicast, multicast, broadcast, NAT, private ranges, CIDR.* - Host identification, subnetting, address conservation * - Anycast - One-to-nearest delivery. Packets go to the closest destination with the shared IP. - Load balancing, DNS, CDN nodes. * - Broadcast - One-to-all delivery within a subnet. IPv4 supports this. - ARP, DHCP discovery. * - CIDR - Classless subnetting with VLSM. Replaces classful addressing. - Route aggregation, modern IP allocation. * - Classful - Legacy method using fixed IP blocks (A, B, C, etc.). - Historical networks. * - Multicast - One-to-many group communication. - Streaming, OSPF, conferencing. * - NAT - Private-to-public IP mapping. - IPv4 conservation, home routers. * - Subnetting - Divides networks into smaller subnets. - IP management, routing control. * - Unicast - One-to-one delivery. - Browsing, file transfers, email. * - EGP (Exterior Gateway Protocol) - One of the earliest routing protocols used to exchange routing info between autonomous systems. Largely obsolete and replaced by BGP. - Inter-AS routing in early networks. * - EIGRP (Enhanced Interior Gateway Routing Protocol) - Cisco proprietary protocol combining features of distance-vector and link-state protocols. Supports VLSM, fast convergence, and uses DUAL algorithm. - Efficient routing within Cisco-based enterprise networks. * - IGRP (Interior Gateway Routing Protocol) - Older Cisco proprietary protocol, now deprecated in favor of EIGRP. Limited scalability and slow convergence. - Legacy enterprise routing. * - IS-IS (Intermediate System to Intermediate System) - Link-state protocol designed for large ISP networks. Scales well and supports both IPv4 and IPv6. - Core ISP and enterprise backbone routing. * - Multiprotocol BGP (MP-BGP) - Extension of BGP that supports routing for multiple protocols, including IPv6 and MPLS VPNs. - Multi-protocol environments and MPLS networks. * - OSPF (Open Shortest Path First) - Open standard link-state protocol using Dijkstra's algorithm. Supports areas, fast convergence, and VLSM. - Hierarchical and scalable enterprise routing. * - RIPv1 (Routing Information Protocol v1) - Early distance-vector protocol using hop count metric. No support for CIDR or VLSM. - Small networks or legacy equipment. * - RIPv2 (Routing Information Protocol v2) - An enhanced version of RIPv1, supporting authentication, CIDR, and multicast updates. - Small-to-medium networks with basic routing needs. .. tab-set:: .. tab-item:: IPv4 Basics **RFC:** RFC 791 **Main Features:** - 32-bit addressing scheme in dotted-decimal format (e.g., `192.168.0.1`) - Operates at OSI Layer 3 (Network Layer) - Provides logical addressing and packet fragmentation - Header includes TTL, checksum, protocol, and source/destination IP - Stateless and connectionless: each packet is treated independently - Widely deployed across all modern networks **Use Cases:** - Core of internet communication - IP routing within and between enterprise networks - Host identification in TCP/IP model **Alternative Protocols:** - IPv6 – Next-generation protocol with larger address space and security - IPX – Legacy Novell protocol (obsolete) - AppleTalk – Deprecated Apple protocol .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: What You Will Learn in This Section **Let us learn more about IPv4:** * :ref:`Learnings in this section ` * :ref:`Terminology ` * :ref:`Version Info ` * :ref:`IPv4 Version&RFC Details ` * :ref:`IPv4 Basic Setup on Ubuntu using IPv4 ` * :ref:`IPv4 Protocol Packet Details ` * :ref:`IPv4 Usecases ` * :ref:`IPv4 Basic Features ` * :ref:`Reference links ` .. button-link:: ./IPv4/ipv4.html :color: primary :shadow: :expand: Jump to "IPv4 Basics" .. tab-set:: .. tab-item:: IPv4 Header Structure **RFC:** RFC 791 **Main Features:** - Fixed 20-byte base header with optional fields - Fields include version, IHL, total length, TTL, protocol, checksum, source & destination IP - Supports fragmentation with Identification, Flags, and Fragment Offset fields - Uses Protocol field to indicate upper-layer (TCP, UDP, etc.) - TTL limits packet lifetime and prevents infinite routing loops - Checksum ensures integrity of the IPv4 header **Use Cases:** - Packet parsing and inspection by firewalls and routers - Deep packet inspection in IDS/IPS systems - Teaching core structure of IP networking - Troubleshooting with tools like Wireshark **Alternative Protocols:** - IPv6 – Simplified header with fixed length and no fragmentation - MPLS – Used in high-performance networks as an alternative to traditional IP routing - GRE – Tunneling protocol that wraps IP headers for encapsulated routing .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: What You Will Learn in This Section **Let us learn more about IPv4 Header Structure:** * :ref:`Learnings in this section ` * :ref:`Terminology ` * :ref:`Version Info ` * :ref:`Header Structure Basic Setup on Ubuntu using IPv4 ` * :ref:`IPv4 Feature : Header Structure ` * :ref:`Reference links ` .. button-link:: ./IPv4/IPv4_Header_Structure.html :color: primary :shadow: :expand: Jump to "IPv4 Header Structure" .. tab-set:: .. tab-item:: IPv4 Packet Routing **RFC:** RFC 791, RFC 1812 **Main Features:** - Routing uses destination IP address and routing tables to forward packets - Decisions are made hop-by-hop, not end-to-end - Routers use static or dynamic routing protocols (e.g., RIP, OSPF, BGP) - Longest prefix match algorithm determines best next hop - TTL is decremented at each router hop to avoid loops - Packets may follow different paths (asymmetric routing) **Use Cases:** - Forwarding IP packets across multiple networks - Enterprise network design and internet backbone routing - Dynamic route learning and failover handling - Implementation of routing policies (e.g., QoS, access control) **Alternative Protocols:** - MPLS – Label-based routing used in service provider networks - IPv6 Routing – Similar logic but with improved features - SDN – Centralized routing control (e.g., OpenFlow) .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: What You Will Learn in This Section **Let us learn more about IPv4 Packet Routing:** * :ref:`Learnings in this section ` * :ref:`Terminology ` * :ref:`Version Info ` * :ref:`Packet Routing Basic Setup on Ubuntu using IPv4 ` * :ref:`IPv4 Feature : Packet Routing ` * :ref:`Reference links ` .. button-link:: ./IPv4/IPv4_Packet_Routing.html :color: primary :shadow: :expand: Jump to "IPv4 Packet Routing" .. tab-set:: .. tab-item:: IPv4 Fragmentation **RFC:** RFC 791 **Main Features:** - Allows large IP packets to be broken into smaller fragments for networks with smaller MTUs - Uses Identification, Flags, and Fragment Offset fields in the IPv4 header - Fragments are reassembled only at the destination host - Routers do not perform reassembly - If a single fragment is lost, the entire datagram is discarded **Use Cases:** - Transmitting large packets over mixed-MTU networks - Interoperability with older or constrained hardware - Understanding MTU, path MTU discovery, and ICMP Fragmentation Needed messages **Alternative Protocols:** - IPv6 – Does not allow routers to fragment packets; fragmentation is host-controlled - GRE/IPSec – Often requires manual fragmentation handling - Path MTU Discovery (PMTUD) – Reduces need for fragmentation .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: What You Will Learn in This Section **Let us learn more about IPv4 Fragmentation:** * :ref:`Learnings in this section ` * :ref:`Terminology ` * :ref:`Version Info ` * :ref:`Fragmentation Basic Setup on Ubuntu using IPv4 ` * :ref:`IPv4 Feature : Fragmentation ` * :ref:`Reference links ` .. button-link:: ./IPv4/IPv4_Fragmentation.html :color: primary :shadow: :expand: Jump to "IPv4 Fragmentation" .. tab-set:: .. tab-item:: IPv4 Connectionless Protocol **RFC:** RFC 791 **Main Features:** - IPv4 is a connectionless protocol: it does not establish a session before sending data - Each datagram is routed independently and may take different paths - No guarantees for delivery, ordering, or duplication prevention - Lightweight and efficient for many applications **Use Cases:** - Stateless communication like DNS, VoIP, video streaming - Protocols that build their own reliability (e.g., TCP) - Systems that prioritize performance over guaranteed delivery **Alternative Protocols:** - IPv6 – Also connectionless - TCP – Adds connection-oriented behavior on top of IP - SCTP – Combines connectionless and connection-oriented properties .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: What You Will Learn in This Section **Let us learn more about IPv4 as a Connectionless Protocol:** * :ref:`Learnings in this section ` * :ref:`Terminology ` * :ref:`Version Info ` * :ref:`Connectionless Protocol Basic Setup on Ubuntu using IPv4 ` * :ref:`IPv4 Feature : Connectionless Protocol ` * :ref:`Reference links ` .. button-link:: ./IPv4/IPv4_Connectionless_Protocol.html :color: primary :shadow: :expand: Jump to "IPv4 Connectionless Protocol" .. tab-set:: .. tab-item:: IPv4 Protocol Identification **RFC:** RFC 791 **Main Features:** - Uses the "Protocol" field in the IPv4 header to indicate the encapsulated transport-layer protocol - Helps the destination system process the packet correctly (e.g., TCP, UDP, ICMP) - 8-bit field supports up to 256 different protocol types - Common values: 6 (TCP), 17 (UDP), 1 (ICMP) **Use Cases:** - Packet inspection and protocol filtering in firewalls - Enabling routers and hosts to properly forward packets to the correct layer - Deep packet inspection in security tools **Alternative Protocols:** - IPv6 – Uses "Next Header" field with similar function - Ethernet Type Field – Similar functionality at data link layer - SCTP – Encapsulates multiple protocols with built-in multiplexing .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: What You Will Learn in This Section **Let us learn more about IPv4 Protocol Identification:** * :ref:`Learnings in this section ` * :ref:`Terminology ` * :ref:`Version Info ` * :ref:`Protocol Identification Basic Setup on Ubuntu using IPv4 ` * :ref:`IPv4 Feature : Protocol Identification ` * :ref:`Reference links ` .. button-link:: ./IPv4/IPv4_Protocol_Identification.html :color: primary :shadow: :expand: Jump to "IPv4 Protocol Identification" .. tab-set:: .. tab-item:: IPv4 Time To Live (TTL) **RFC:** RFC 791 **Main Features:** - TTL field is an 8-bit value in the IPv4 header - Limits the lifespan of a packet by specifying the number of hops allowed - Decremented by 1 at each router hop; discarded when TTL reaches 0 - Prevents infinite loops caused by routing misconfigurations **Use Cases:** - Loop prevention in IP routing - Diagnostics using `traceroute` and TTL expiration - Detecting network topology or delays **Alternative Protocols:** - IPv6 – Replaces TTL with "Hop Limit" field, serving the same purpose - ICMP – Used in conjunction with TTL for `Time Exceeded` messages - MPLS TTL – Similar mechanism in label-switched paths .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: What You Will Learn in This Section **Let us learn more about IPv4 Time To Live (TTL):** * :ref:`Learnings in this section ` * :ref:`Terminology ` * :ref:`Version Info ` * :ref:`Time to Live Basic Setup on Ubuntu using IPv4 ` * :ref:`IPv4 Feature : TTL (Time to Live) ` * :ref:`Reference links ` .. button-link:: ./IPv4/IPv4_Time_to_Live.html :color: primary :shadow: :expand: Jump to "IPv4 Time To Live (TTL)" .. tab-set:: .. tab-item:: IPv4 Addressing **RFCs:** RFC 791, RFC 950, RFC 1918, RFC 3022 **Main Features:** - 32-bit address space with ~4.3 billion addresses - **Address Types:** - Unicast: one-to-one - Broadcast: one-to-all on subnet (255.255.255.255) - Multicast: Class D (224.0.0.0 – 239.255.255.255) - **CIDR** (Classless Inter-Domain Routing): /n format for flexible subnetting - **Private Address Ranges:** - 10.0.0.0/8 - 172.16.0.0/12 - 192.168.0.0/16 - **NAT:** Translates private addresses to public for internet access **Use Cases:** - Host IP allocation in enterprise and ISP networks - Internet access via NAT from private IPs - Network segmentation via subnetting **Alternative Protocols:** - IPv6 – Uses 128-bit address space and does not require NAT - DHCP – For automatic IP address assignment - MAC – Layer 2 addressing (hardware level) .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: What You Will Learn in This Section **Let us learn more about IPv4 Addressing:** .. button-link:: ./IPv4/IPv4_Addressing.html :color: primary :shadow: :expand: Jump to "IPv4 Addressing" .. tab-set:: .. tab-item:: Anycast **RFC:** RFC 1546 **Main Features:** - One-to-nearest delivery based on routing metrics. - Multiple hosts share the same IP. **Use Cases:** - DNS root servers - Content delivery networks (CDNs) - Load balancing in routing .. panels:: :container: container pb-4 :column: col-lg-12 p-2 **Learn More About Anycast:** * :ref:`Learnings in this section ` * :ref:`Terminology ` * :ref:`Version Info ` * :ref:`Anycast_Addressing Version&IEEE Details ` * :ref:`Anycast_Addressing Basic Setup on Ubuntu using IPv4 ` * :ref:`Anycast_Addressing Basic Setup on Ubuntu using IPv6 ` * :ref:`Anycast_Addressing Protocol Packet Details ` * :ref:`Anycast_Addressing Usecases ` * :ref:`Anycast_Addressing Basic Features ` * :ref:`Reference links ` .. button-link:: ./IPv4/IPv4_Addressing_Anycast_Addressing.html :color: primary :shadow: :expand: Jump to "Anycast" .. tab-set:: .. tab-item:: Broadcast **RFC:** RFC 919, RFC 922 **Main Features:** - One-to-all within subnet. - IPv4 only; IPv6 does not support broadcast. **Use Cases:** - ARP discovery - DHCPDISCOVER messages .. panels:: :container: container pb-4 :column: col-lg-12 p-2 **Learn More About Broadcast:** * :ref:`Learnings in this section ` * :ref:`Terminology ` * :ref:`Version Info ` * :ref:`Broadcast_Addessing Version&IEEE Details ` * :ref:`Broadcast_Addessing Basic Setup on Ubuntu using IPv4 ` * :ref:`Broadcast_Addessing Protocol Packet Details ` * :ref:`Broadcast_Addessing Usecases ` * :ref:`Broadcast_Addessing Basic Features ` * :ref:`Reference links ` .. button-link:: ./IPv4/IPv4_Addressing_Broadcast_Addressing.html :color: primary :shadow: :expand: Jump to "Broadcast" .. tab-set:: .. tab-item:: CIDR **RFC:** RFC 4632 **Main Features:** - Replaces classful addressing. - Allows subnetting with variable-length subnet masks. **Use Cases:** - Route summarization - IP space efficiency in ISPs .. panels:: :container: container pb-4 :column: col-lg-12 p-2 **Learn More About CIDR:** * :ref:`Learnings in this section ` * :ref:`Terminology ` * :ref:`Version Info ` * :ref:`Classful_Addressing Version&IEEE Details ` * :ref:`Classful_Addressing Basic Setup on Ubuntu using IPv4 ` * :ref:`Classful_Addressing Protocol Packet Details ` * :ref:`Classful_Addressing Usecases ` * :ref:`Classful_Addressing Basic Features ` * :ref:`Reference links ` .. button-link:: ./IPv4/IPv4_Addressing_CIDR.html :color: primary :shadow: :expand: Jump to "CIDR" .. tab-set:: .. tab-item:: Classful **RFC:** RFC 791 (conceptual, now obsolete) **Main Features:** - Divides address space into Class A, B, C, etc. - Lacks flexibility, poor address utilization. **Use Cases:** - Legacy IP networks - Educational/historical references .. panels:: :container: container pb-4 :column: col-lg-12 p-2 **Learn More About Classful Addressing:** * :ref:`Learnings in this section ` * :ref:`Terminology ` * :ref:`Version Info ` * :ref:`Classful_Addressing Version&IEEE Details ` * :ref:`Classful_Addressing Basic Setup on Ubuntu using IPv4 ` * :ref:`Classful_Addressing Protocol Packet Details ` * :ref:`Classful_Addressing Usecases ` * :ref:`Classful_Addressing Basic Features ` * :ref:`Reference links ` .. button-link:: ./IPv4/IPv4_Addressing_Classful_Addressing.html :color: primary :shadow: :expand: Jump to "Classful" .. tab-set:: .. tab-item:: Multicast **RFC:** RFC 1112, RFC 5771 **Main Features:** - One-to-many group delivery. - More efficient than broadcast for large-scale data. **Use Cases:** - IPTV - Video conferencing - OSPF, PIM routing updates .. panels:: :container: container pb-4 :column: col-lg-12 p-2 **Learn More About Multicast:** * :ref:`Learnings in this section ` * :ref:`Terminology ` * :ref:`Version Info ` * :ref:`Multicast_Addressing Version&IEEE Details ` * :ref:`Multicast_Addressing Basic Setup on Ubuntu using IPv4 ` * :ref:`Multicast_Addressing Protocol Packet Details ` * :ref:`Multicast_Addressing Usecases ` * :ref:`Multicast_Addressing Basic Features ` * :ref:`Reference links ` .. button-link:: ./IPv4/IPv4_Addressing_Multicast_Addressing.html :color: primary :shadow: :expand: Jump to "Multicast" .. tab-set:: .. tab-item:: NAT **RFC:** RFC 3022 **Main Features:** - Translates private IP to public. - Extends IPv4 usability and adds a security layer. **Use Cases:** - Home/enterprise firewalls - ISPs managing limited IPv4 blocks .. panels:: :container: container pb-4 :column: col-lg-12 p-2 **Learn More About NAT:** * :ref:`Learnings in this section ` * :ref:`Terminology ` * :ref:`Version Info ` * :ref:`NAT Version&RFC Details ` * :ref:`NAT Basic Setup on Ubuntu using IPv4 ` * :ref:`NAT Usecases ` * :ref:`NAT Basic Features ` * :ref:`NAT Feature : IP Address Translation ` * :ref:`NAT Feature : Port Address Translation (PAT) ` * :ref:`NAT Feature : Conserves IPv4 Addresses ` * :ref:`NAT Feature : Enhances Network Security ` * :ref:`NAT Feature : Supports Multiple NAT Types ` * :ref:`NAT Feature : Protocol-Aware Behavior ` * :ref:`NAT Feature : Enables Internet Access for Private Networks ` * :ref:`Reference links ` .. button-link:: ./IPv4/IPv4_Addressing_NAT.html :color: primary :shadow: :expand: Jump to "NAT" .. tab-set:: .. tab-item:: Subnetting **RFC:** RFC 950 **Main Features:** - Divides larger IP space into smaller, manageable parts. - Enhances routing and security. **Use Cases:** - Enterprise internal segmentation - ISP hierarchical IP design .. panels:: :container: container pb-4 :column: col-lg-12 p-2 **Learn More About Subnetting:** * :ref:`Learnings in this section ` * :ref:`Terminology ` * :ref:`Version Info ` * :ref:`Subnetting Version&IEEE Details ` * :ref:`Subnetting Basic Setup on Ubuntu using IPv4 ` * :ref:`Subnetting Protocol Packet Details ` * :ref:`Subnetting Usecases ` * :ref:`Subnetting Basic Features ` * :ref:`Reference links ` .. button-link:: ./IPv4/IPv4_Addressing_Subnetting.html :color: primary :shadow: :expand: Jump to "Subnetting" .. tab-set:: .. tab-item:: Unicast **RFC:** RFC 791 **Main Features:** - One-to-one data transfer. - Most common form of IP communication. **Use Cases:** - Web browsing - Emails, file sharing .. panels:: :container: container pb-4 :column: col-lg-12 p-2 **Learn More About Unicast:** * :ref:`Terminology ` * :ref:`Version Info ` * :ref:`Unicast_Addressing Version&IEEE Details ` * :ref:`Unicast_Addressing Basic Setup on Ubuntu using IPv4 ` * :ref:`Unicast_Addressing Protocol Packet Details ` * :ref:`Unicast_Addressing Usecases ` * :ref:`Unicast_Addressing Basic Features ` * :ref:`Reference links ` .. button-link:: ./IPv4/IPv4_Addressing_Unicast_Addressing.html :color: primary :shadow: :expand: Jump to "Unicast" .. tab-set:: .. tab-item:: EGP (Exterior Gateway Protocol) **RFC:** RFC 904, RFC 1772 (Historic) **Main Features:** - One of the earliest routing protocols used to exchange routing info between autonomous systems. - Largely obsolete and replaced by BGP. **Use Cases:** - Inter-AS routing in early networks. **Alternative Protocols:** - BGP – Modern exterior gateway protocol used globally. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: What You Will Learn in This Section **Let us learn more about EGP:** * :ref:`Learnings in this section ` * :ref:`Terminology ` * :ref:`Version Info ` * :ref:`EGP Version&RFC Details ` * :ref:`EGP Basic Setup on Ubuntu using IPv4 ` * :ref:`EGP Basic Setup on Ubuntu using IPv6 ` * :ref:`EGP Protocol Packet Details ` * :ref:`EGP Usecases ` * :ref:`EGP Basic Features ` * :ref:`EGP Feature : Inter-AS Communication ` * :ref:`EGP Feature : Reachability-Based Routing ` * :ref:`EGP Feature : Polling Mechanism ` * :ref:`EGP Feature : Finite-State Machine Model ` * :ref:`EGP Feature : Simple Packet Structure ` * :ref:`EGP Feature : Tree-Like Topology Support ` * :ref:`EGP Feature : Limited Scalability ` * :ref:`Reference links ` .. button-link:: ./IPv4/EGP.html :color: primary :shadow: :expand: Jump to "EGP" .. tab-set:: .. tab-item:: IS-IS (Intermediate System to Intermediate System) **RFC:** RFC 1142, RFC 1195, RFC 5308 (IPv6 support) **Main Features:** - Link-state protocol designed for large ISP networks. - Scales well and supports both IPv4 and IPv6. **Use Cases:** - Core ISP and enterprise backbone routing. **Alternative Protocols:** - OSPF – Another scalable link-state protocol. - BGP – For inter-domain routing. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: What You Will Learn in This Section **Let us learn more about IS-IS:** * :ref:`Learnings in this section ` * :ref:`Terminology ` * :ref:`Version Info ` * :ref:`IS_IS Version&RFC Details ` * :ref:`IS_IS Basic Setup on Ubuntu using IS_IS ` * :ref:`IS_IS Basic Setup on Ubuntu using IS_IS ` * :ref:`IS_IS Protocol Packet Details ` * :ref:`IS_IS Usecases ` * :ref:`IS_IS Basic Features ` * :ref:`IS_IS Feature : Link-State Protocol ` * :ref:`IS_IS Feature : Interior Gateway Protocol (IGP) ` * :ref:`IS_IS Feature : Supports Hierarchical Routing ` * :ref:`IS_IS Feature : Protocol Extensibility via TLVs ` * :ref:`IS_IS Feature : IPv4 and IPv6 Support ` * :ref:`IS_IS Feature : Fast Convergence ` * :ref:`IS_IS Feature : Scalability ` * :ref:`IS_IS Feature : Authentication Support ` * :ref:`IS_IS Feature : Segment Routing Support ` * :ref:`Reference links ` .. button-link:: ./IPv4/IS_IS.html :color: primary :shadow: :expand: Jump to "IS-IS" .. tab-set:: .. tab-item:: MP-BGP (Multiprotocol BGP) **RFC:** RFC 4271 (BGP-4), RFC 4760 (Multiprotocol Extensions) **Main Features:** - Extension of BGP that supports routing for multiple protocols, including IPv6 and MPLS VPNs. **Use Cases:** - Multi-protocol environments and MPLS networks. **Alternative Protocols:** - EIGRP – For internal routing within organizations. - IS-IS – Alternative backbone routing protocol. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: What You Will Learn in This Section **Let us learn more about MP-BGP:** * :ref:`Learnings in this section ` * :ref:`Terminology ` * :ref:`Version Info ` * :ref:`MP_BGP Version&RFC Details ` * :ref:`MP_BGP Basic Setup on Ubuntu using IPv4 ` * :ref:`MP_BGP Protocol Packet Details ` * :ref:`MP_BGP Usecases ` * :ref:`MP_BGP Basic Features ` * :ref:`MP_BGP Feature : Multiprotocol Support ` * :ref:`MP_BGP Feature : AFI_SAFI Mechanism ` * :ref:`MP_BGP Feature : MP_REACH_NLRI Attribute ` * :ref:`MP_BGP Feature : MP_UNREACH_NLRI Attribute ` * :ref:`MP_BGP Feature : Backward Compatibility ` * :ref:`MP_BGP Feature : Separate Routing Tables ` * :ref:`MP_BGP Feature : Flexible Transport ` * :ref:`MP_BGP Feature : Scalability ` * :ref:`MP_BGP Feature : Policy Control ` * :ref:`MP_BGP Feature : Extensibility ` * :ref:`Reference links ` .. button-link:: ./IPv4/MP_BGP.html :color: primary :shadow: :expand: Jump to "MP-BGP" .. tab-set:: .. tab-item:: OSPF (Open Shortest Path First) **RFC:** RFC 2328 (OSPFv2) **Main Features:** - Open standard link-state protocol using Dijkstra’s algorithm. - Supports areas, fast convergence, and VLSM. **Use Cases:** - Hierarchical and scalable enterprise routing. **Alternative Protocols:** - IS-IS – Another open standard link-state protocol. - EIGRP – Cisco proprietary alternative. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: What You Will Learn in This Section **Let us learn more about OSPF:** * :ref:`Learnings in this section ` * :ref:`Terminology ` * :ref:`Version Info ` * :ref:`OSPF Version&RFC Details ` * :ref:`OSPF Basic Setup on Ubuntu using OSPF ` * :ref:`OSPF Basic Setup on Ubuntu using OSPF ` * :ref:`OSPF Protocol Packet Details ` * :ref:`OSPF Usecases ` * :ref:`OSPF Basic Features ` * :ref:`OSPF Feature : Link-State Protocol ` * :ref:`OSPF Feature : Hierarchical Design ` * :ref:`OSPF Feature : Fast Convergence ` * :ref:`OSPF Feature : Cost-Based Metric ` * :ref:`OSPF Feature : Supports VLSM and CIDR ` * :ref:`OSPF Feature : Multicast Updates ` * :ref:`OSPF Feature : Authentication Support ` * :ref:`OSPF Feature : DR BDR Election ` * :ref:`OSPF Feature : Equal-Cost Multipath (ECMP) ` * :ref:`OSPF Feature : Scalable and Extensible ` * :ref:`Reference links ` .. button-link:: ./IPv4/OSPF.html :color: primary :shadow: :expand: Jump to "OSPF" .. tab-set:: .. tab-item:: RIPv1 (Routing Information Protocol v1) **RFC:** RFC 1058 **Main Features:** - Early distance-vector protocol using hop count metric. - No support for CIDR or VLSM. **Use Cases:** - Small networks or legacy equipment. **Alternative Protocols:** - RIPv2 – Improved version with modern features. - OSPF – For larger or more complex networks. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: What You Will Learn in This Section **Let us learn more about RIPv1:** * :ref:`Learnings in this section ` * :ref:`Terminology ` * :ref:`Version Info ` * :ref:`RIPv1 Version&RFC Details ` * :ref:`RIPv1 Basic Setup on Ubuntu using IPv4 ` * :ref:`RIPv1 Basic Setup on Ubuntu using IPv6 ` * :ref:`RIPv1 Protocol Packet Details ` * :ref:`RIPv1 Usecases ` * :ref:`RIPv1 Basic Features ` * :ref:`RIPv1 Feature : Classful Routing ` * :ref:`RIPv1 Feature : Distance Vector Protocol ` * :ref:`RIPv1 Feature : Maximum Hop Count ` * :ref:`RIPv1 Feature : Broadcast Updates ` * :ref:`RIPv1 Feature : Periodic Updates ` * :ref:`RIPv1 Feature : No Authentication ` * :ref:`Reference links ` .. button-link:: ./IPv4/RIPv1.html :color: primary :shadow: :expand: Jump to "RIPv1" .. tab-set:: .. tab-item:: RIPv2 (Routing Information Protocol v2) **RFC:** RFC 2453 **Main Features:** - An enhanced version of RIPv1, supporting authentication, CIDR, and multicast updates. **Use Cases:** - Small-to-medium networks with basic routing needs. **Alternative Protocols:** - OSPF – More scalable and feature-rich. - EIGRP – Cisco proprietary alternative. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: What You Will Learn in This Section **Let us learn more about RIPv2:** * :ref:`Learnings in this section ` * :ref:`Terminology ` * :ref:`Version Info ` * :ref:`RIPv2 Version&RFC Details ` * :ref:`RIPv2 Basic Setup on Ubuntu using IPv4 ` * :ref:`RIPv2 Basic Setup on Ubuntu using IPv6 ` * :ref:`RIPv2 Protocol Packet Details ` * :ref:`RIPv2 Usecases ` * :ref:`RIPv2 Basic Features ` * :ref:`RIPv2 Feature : Classless Routing ` * :ref:`RIPv2 Feature : Distance Vector Protocol ` * :ref:`RIPv2 Feature : Maximum Hop Count ` * :ref:`RIPv2 Feature : Multicast Updates ` * :ref:`RIPv2 Feature : Periodic Updates ` * :ref:`RIPv2 Feature : Authentication Support ` * :ref:`Reference links ` .. button-link:: ./IPv4/RIPv2.html :color: primary :shadow: :expand: Jump to "RIPv2"