LAN & Enterprise


This documentation is related to typical LAN technologies found in Enterprise or End Customer networks. This includes IGP, multicasting, switching and Customer Edge systems like NAT or Firewall Security.

  • OSPF Stub Area Types: A quick reference view of the different OSPF Stub Area types, how they’re configured and what LSAs are flooded where.
  • OSPF LSA Types: A reference sheet for all the OSPF LSA Types supported by Cisco with details of their contents, scope and general usage.
  • OSPF Security: A snapshot of how to configure OSPF neighbor/area authentication and encryption. This document covers both OSPFv2 and OSPFv3 for both IOS-XE and IOS-XR.
  • EIGRP Key Chains: A handy diagram showing the steps necessary to configure EIGRP authentication.

  • NAT Types: Inside and Outside NAT vs. Local and Global NAT is a bit confusing. Use this diagram as a quick reference to keep it straight in your head:

  • IGMPv2 Queries, Reports and Timers: Shows the basics of who sends what queries/reports to who and how often they are sent.

  • IPv6 Router Solicitation/Advertisement Sequence and Address Resolution:  Shows the basics of RS and RA exchanges in IPv6 as well as Address Resolution (the equivalent of ARP in IPv4).

  • OSPF and EIGRP Neighborship Requirements:  Useful mnemonic device to help remember the neighborship requirements for OSPF and EIGRP neighbours. MMANTRAPS.

  • Destination Multicast MAC Address Calculation:  This shows how the destination multicast MAC address is calculated from the destination multicast IPv4 address. It also breaks down how and why there is an overlap of multiple Class D multicast addresses to a single destination MAC.

  • Embedded RP in IPv6 Multicast:  Shows the breakdown of the calculation used to determine the RP address when Embedded RP addressing is used in IPv6 Multicast

  • Etherchannel: This document gives a good cheat-sheet style overview of Etherchannel technology, showing the configuration of both PAgP and LACP.

  • Reading an SNMP MIB: Using mib 2 as an example, this document details how to read and interpret an SNMP MIB that uses the SMIv1 standard.

  • First Hop Redundancy Protocol – Quick Reference Table: A summary table showing FHRP protocols and their characteristics. Handy for comparing the different technologies.
  • Performing a debug on a Junos SRX: A very quick and dirty step-by-step outline of how to perform debugging on a Juno SRX Firewall
  • Type of Service Byte – IP Precedence and DSCP: A summarised overview of the ToS Byte and how it relates to IP Precedence and DSCP. Perfect for anyone studying QoS.
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