OSPF Routing Protocol is the most used protocol in the world, especially in the world of service provider, through this hand-on-labs workbook, you will discover another aspect of OSPF which is the RFCs that stands for “Request For Comments”, A Request for Comments (RFC) is a formal document developed by a committee of the Internet Engineering Task Force (IETF) and subsequently reviewed by interested parties. Memos in the RFC document series contain technical and organizational notes about the Internet. They cover many aspects of computer networking, including protocols.
One of these internet protocols, OSPF is described in many RFCs, and why it is important to read and understand these RFCs? because there are many differences about path selection and behaviors between them such as Type 7 translation, summary cost, forward address, and so on, this impact is very important to know it in order to interpret an OSPF behavior.
This new approach of OSPF with RFC changes drastically the traditional path selection based on: 1-ROUTE TYPE and 2-COST.
The changes are huge, another order of selection should be taken in consideration with RFC.
Goals and Methods:
The goal of this atypical and unique book in the world about OSPF Routing Protocol: is to translate the RFCs into Practice through 101 uncommon scenarios.It is written with atypical scenarios and explained with another view, in constrast with other resources, the only book in the market that explains OSPF with RFCs Request For Comments, more important, demystifying the different RFC ‘s behavior regarding path selection, NSSA Area options with RFC 1587 and 3101, OSPFv2 and OSPFv3 ‘s behavior when moving from RFC 1583 to RFC 2328 and from RFC 1583 to RFC 5340 respectively.
Understanding how the RFCs explain OSPF is very important, it gives you a way to look inside OSPF Packets, such as LSA Types, LSDB and NSSA Area Types and demystifying the most misunderstanding OSPF’s behavior, such as LSA Types, Area Types, Network Types OSPF Path Selection, Route Filtering, Forwarding Address, Prefix Suppression, Loop-Free Alternate, Summary Routes and so on.
To understand what inside OSPF LSAs, what happen and why this happen? for example: why the P-bit should be cleared in some situations and why it should be set, why the Forward Address must be set and why it must cleared, how suboptimal routing or routing loop can occur in OSPF and so on.
Many questions are answered in 101 scenarios step by step that you will not find elsewhere.
By traveling through this workbook you will:
- Be able to troubleshoot any problem by reasoning.
- Be able to answer amazing challenges that requires only one command.
This workbook provides you challenges where you will learn:
- How to follow some logic to detect any problem or to explain an unexpected behavior.
- How to fix it with some restrictions such as: you are not allowed to use cost and so on.
Understanding OSPF needs atypical and uncommon explanations, useful and appropriate show commands and debug commands rather than showing just routing tables or LSDB tables.
As you read this book, you definitely get a feeling of, “This is how a feature works”, “This is how to understand a behavior” and “This is how to solve a problem”.
How to read this book?
This book is a series of hands of labs, and there is no relationship between them, you can start at any lab, from the last, the first or the middle, the purpose is to provide you a granularity to freely switch between topics and go to the one you need in depth lecture and understanding.
This workbook needs a solid knownledges so that you can understand and reproduce the scenarios.
Table of contents
Lab 1: RFC 3101 and RFC 1587 with OSPFv2
Lab 2: RFC 3101 and RFC 1587 with OSPFv3 Address Family
Lab 3: NSSA ABRs translator with RFC 3101 and 1587 and Nt bit
Lab 4: RFC 5340 and the next-hop for OSPFv3 routes
Lab 5: RFC 1583 and RFC 2328 for the Summary route
Lab 6: RFC 5340 and RFC 1583 for OSPFv3 address family and external path preference
Lab 7: RFC 5340 and RFC 1583 for OSPFv3 address family with multiple ASBR
Lab 8: OSPFv2 external path selection demystified with RFC 3101 and 1587
Lab 9: RFC 1587 and RFC 5340 with OSPFv3 Address Family
Lab 10: P-bit loop prevention mechanism with RFC 3101 and 1587
Lab 11: OSPFv3 Address Family Challenge Lab with RFC 5340
Lab 12: OSPFv3 AF IPv4 and IPv6 RFC 3101 and 1587 with Prefix-Suppression
Lab 13: OSPF ABR NSSA originating both Type-7 and 5 LSAs and optimization
Lab 14: RFC 3509 and ABR behavior with Type-3 and Type -4 LSAs
Lab 15: NSSA ABR and Type-7 selection according to RFC 3101
Lab 16: RFC 1587 and RFC 1583 Compatibility with OSPFv3 Address Family
Lab 17: External path preference in multiple area with RFC 3101 and 1587
Lab 18: Reducing or Blocking LSA flooding and DNA bit
Lab 19: RFC 3101 and RFC 1587 OSPFv2 OSPFv3 P-bit cleared
Lab 20: RFC 3101 and RFC 1587 on an NSSA ABR
Lab 21: OSPFv3 AF challenge with RFC
Lab 22: OSPF Multi-Area Adjacency and RFC 5185
Lab 23: OSPFv3 Forward Address and RFC 5340
Lab 24: Two Type-7 LSA with two ASBRs and RFC 3101
Lab 25: P-bit set and P-bit cleared with RFC 3101 in OSPFv2
Lab 26: OSPF-4-FLOOD_WAR message
Lab 27: Two Type-5 LSA with overlapping subnet and RFC 2328
Lab 28: OSPFv3 AF demystified with RFC 3101 1587 1583 5340
Lab 29: Why the P-bit must be cleared in the Type-7 default route?
Lab 30: Why an NSSA ABR does not inject a default route automatically?
Lab 31: Why it is not good to redistribute into a backbone area?
Lab 32: Routing loop with RFC 1583 and 5340
Lab 33: OSPFv3 suboptimal routing with multiple ABRs
Lab 34: Capability Transit and Breaking the split horizon rule
Lab 35: How to inject external route into Stub Area
Lab 36: Virtual-Link and the DNA (DoNoAge) bit demand circuit and authentication
Lab 37: LSInfinity for inter-area prefix External and Router LSAs
Lab 38: OSPFv3 Stub router advertisement and RFC 6987
Lab 39: Demystify OSPFv2 external path selection
Lab 40: P-bit loop prevention mechanism and connectivity issues
Lab 41: Prefix Suppression and RFC 6860 issue with Type-2 LSA
Lab 42: How to set the P-bit in Type-7 LSA
Lab 43: NSSA ABR translation condition
Lab 44: OSPF Prefix-Suppression with OSPFv3 Address Family
Lab 45: Type-7 LSA Default route on an NSSA ASBR
Lab 46: Type-9 LSA in Broadcast and Point-To-Point Networks
Lab 47: OSPF external path selection with multiple ASBRs Type -1 and Type-2
Lab 48: OSPFv2 external path selection multiple ASBRs
Lab 49: OSPF external route filtering without distribute-list
Lab 50: OSPFv3 distribute list filtering demystified
Lab 51: show ipv6 ospf neighbor command demystified
Lab 52: OSPFv3 external route summary cost and RFC 3101
Lab 53: NSSA external route demystified with RFC 3101
Lab 54: MPLS VPN and OSPF Down bit loop prevention
Lab 55: OSPF sham link on MPLS VPN
Lab 56: RFC 2328 and Suboptimal Routing for external prefix
Lab 57: ABR loop prevention with Inter-area routing and P-bit
Lab 58: OSPF TTL security check
Lab 59: OSPF Network Type demystified with Type-1 LSA
Lab 60: Effect of RFC 1583 and 2328 on NSSA area
Lab 61: OSPFv3 filter-list NSSA and RFC 1583 2328
Lab 62: RFC 5243 Database Exchange Summary Optimization
Lab 63: Largest area id as a tie breaker with RFC 3101 and RFC 2328 scenario 1
Lab 64: Largest area id as a tie breaker with RFC 3101 and RFC 2328 scenario 2
Lab 65: inter-area loop prevention and discard route issues
Lab 66: Capability Transit feature and suboptimal routing
Lab 67: Capability Transit feature and routing loop
Lab 68: OSPFv3 suboptimal routing with multiple NSSA ABR
Lab 69: OSPF local-rib-criteria forwarding-address command
Lab 70: OSPF local-rib-criteria nssa-translation command
Lab 71: How to configure an area as a non-transit area
Lab 72: Intra-area concept and Transit Capability
Lab 73: The max-lsa OSPF Router Subcommand
Lab 74: OSPF SPF Throttling and routing loop
Lab 75: SPF Algorithm and the effect of the Type-9 LSA
Lab 76: LSA Type 1 and LSA Type 3 SPF calculation
Lab 77: Type-3 and Type-4 LSAs loop prevention and the suboptimal routing on OSPFv3
Lab 78: Default-information originate with always keyword and loop prevention
Lab 79: OSPFv3 for IPv4 using Address Family
Lab 80: OSPFv3 Address Families stub and Totally Stubby area
Lab 81: NSSA Forward Address Filter-List Default route
Lab 82: External Prefix propagation on OSPFv3
Lab 83: Router LSA and prefix-suppression
Lab 84: Router and Summary LSAs in Virtual-Link
Lab 85: Intra-Area and Inter-Area routes propagation
Lab 86: NSSA for external prefix and secondary address
Lab 87: asb-Summary Type-4 LSA Demystified
Lab 88: Inter-area router LSA loop prevention in OSPFv3
Lab 89: Inter-area prefix LSA loop prevention in OSPFv3
Lab 90: Link-State Database of OSPFv3 demystified
Lab 91: V-bit and B-bit fields in Type-1 LSA
Lab 92: How to build OSPFv2 topology using LSDB
Lab 93: How to build OSPFv2 topology using LSDB
Lab 94: Type-4 LSA generation
Lab 95: OSPF Discrepancy
Lab 96: OSPF Virtual-Link Max-LSA and ISPF
Lab 97: DMVPN Phase 2 OSPF Broadcast Versus Point to Multipoint Network Type
Lab 98: OSPFv3 External Path Selection Demystified With Multiple RFC
Lab 99: Routing Problem with OSPF Forwarding Address
Lab 100: Type-2 LSA Demystified On OSPFv2 and OSPFv3
Lab 101: P-bit Policy Paradox
Request For Comments RFC references