IS_IS - Intermediate System to Intermediate System ===================================================== .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **What is IS-IS?** IS-IS (Intermediate System to Intermediate System) is a link-state interior gateway protocol (IGP) used to move information efficiently within a computer network, a group of physically connected computers or devices. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **What is the purpose of IS-IS?** IS-IS is used to determine the best path for data to travel across a network. It helps routers exchange information about network topology to build a complete map of the network. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **What are the levels in IS-IS?** * Level 1 (L1): Intra-area routing * Level 2 (L2): Inter-area routing * Level 1-2: Acts as a gateway between areas .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **What is an IS-IS area?** An IS-IS area is a logical grouping of routers. Routers within the same area share detailed topology information, while routers in different areas share summarized information. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **What are the advantages of IS-IS?** * Scales well in large networks * Flexible and extensible via TLVs * Stable and efficient convergence * Less CPU-intensive compared to OSPF in some cases .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Which OSI Layer does IS-IS operate at?** * IS-IS operates at the **Network Layer (Layer 3)** of the OSI model. * It manages routing and forwarding of data packets within and between areas. * It works closely with Layer 3 protocols to ensure efficient path selection. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow Topics in this section, * :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 ` .. _IS_IS_step1: .. tab-set:: .. tab-item:: Learnings in this section * In this section, you are going to learn .. _IS_IS_step2: .. tab-set:: .. tab-item:: Terminology * Terminology .. _IS_IS_step3: .. tab-set:: .. tab-item:: Version Info * Version Info .. _IS_IS_step5: .. tab-set:: .. tab-item:: IS_IS Version&RFC Details .. csv-table:: :file: ./IS_IS/IS_IS_Version_RFC_details.csv :widths: 10,10,10,30 :header-rows: 1 .. _IS_IS_step19: .. tab-set:: .. tab-item:: IS_IS Basic Setup on Ubuntu using IPv4 * Setup .. _IS_IS_step20: .. tab-set:: .. tab-item:: IS_IS Basic Setup on Ubuntu using IPv6 * Setup .. _IS_IS_step6: .. tab-set:: .. tab-item:: IS_IS Protocol Packet Details **IS_IS Hello PDU (IIH) Packet** .. csv-table:: :file: ./IS_IS/IS_IS_Packetdetails1.csv :widths: 10,20,30,10 :header-rows: 1 **IS_IS Link State PDU (LSP) Packet** .. csv-table:: :file: ./IS_IS/IS_IS_Packetdetails2.csv :widths: 10,20,30,10 :header-rows: 1 **IS_IS Complete Sequence Numbver PDU (CSNP) Packet** .. csv-table:: :file: ./IS_IS/IS_IS_Packetdetails3.csv :widths: 10,20,30,10 :header-rows: 1 **IS_IS Partial Sequence Number PDU (PSNP) Packet** .. csv-table:: :file: ./IS_IS/IS_IS_Packetdetails4.csv :widths: 10,20,30,10 :header-rows: 1 .. _IS_IS_step7: .. tab-set:: .. tab-item:: IS_IS Usecases .. csv-table:: :file: ./IS_IS/IS_IS_Use_Cases.csv :widths: 10,20,30 :header-rows: 1 .. _IS_IS_step8: .. tab-set:: .. tab-item:: IS_IS Basic Features .. csv-table:: :file: ./IS_IS/IS_IS_Basic_Features.csv :widths: 10,10,30 :header-rows: 1 .. _IS_IS_step9: .. tab-set:: .. tab-item:: IS_IS Feature : Link-State Protocol **Link-State Protocol - Testcases** .. csv-table:: :file: ./IS_IS/IS_IS_Feature1_Link_State_Protocol_TestCases.csv :widths: 10,10,30,20 :header-rows: 1 .. _IS_IS_step10: .. tab-set:: .. tab-item:: IS_IS Feature : Interior Gateway Protocol (IGP) **Interior Gateway Protocol (IGP) - Testcases** .. csv-table:: :file: ./IS_IS/IS_IS_Feature2_Interior_Gateway_Protocol_IGP_TestCases.csv :widths: 10,10,30,20 :header-rows: 1 .. _IS_IS_step11: .. tab-set:: .. tab-item:: IS_IS Feature : Supports Hierarchical Routing **Supports Hierarchical Routing - Testcases** .. csv-table:: :file: ./IS_IS/IS_IS_Feature3_Supports_Hierarchical_Routing_TestCases.csv :widths: 10,10,30,20 :header-rows: 1 .. _IS_IS_step12: .. tab-set:: .. tab-item:: IS_IS Feature : Protocol Extensibility via TLVs **Protocol Extensibility via TLVs - Testcases** .. csv-table:: :file: ./IS_IS/IS_IS_Feature4_Protocol_Extensibility_via_TLVs_TestCases.csv :widths: 10,10,30,20 :header-rows: 1 .. _IS_IS_step13: .. tab-set:: .. tab-item:: IS_IS Feature : IPv4 and IPv6 Support **IPv4 and IPv6 Support - Testcases** .. csv-table:: :file: ./IS_IS/IS_IS_Feature5_IPv4_and_IPv6_Support_TestCases.csv :widths: 10,10,30,20 :header-rows: 1 .. _IS_IS_step14: .. tab-set:: .. tab-item:: IS_IS Feature : Fast Convergence **Fast Convergence - Testcases** .. csv-table:: :file: ./IS_IS/IS_IS_Feature6_Fast_Convergence_TestCases.csv :widths: 10,10,30,20 :header-rows: 1 .. _IS_IS_step15: .. tab-set:: .. tab-item:: IS_IS Feature : Scalability **Scalability - Testcases** .. csv-table:: :file: ./IS_IS/IS_IS_Feature7_Scalability_Test_Cases.csv :widths: 10,10,30,20 :header-rows: 1 .. _IS_IS_step16: .. tab-set:: .. tab-item:: IS_IS Feature : Authentication Support **Authentication Support - Testcases** .. csv-table:: :file: ./IS_IS/IS_IS_Feature8_Authentication_Support_TestCases.csv :widths: 10,10,30,20 :header-rows: 1 .. _IS_IS_step17: .. tab-set:: .. tab-item:: IS_IS Feature : Segment Routing Support **Segment Routing Support - Testcases** .. csv-table:: :file: ./IS_IS/IS_IS_Feature9_Segment_Routing_Support_TestCases.csv :widths: 10,10,30,20 :header-rows: 1 .. _IS_IS_step18: .. tab-set:: .. tab-item:: Reference links * Reference links