Above is the logical Topology of how I cabled / Trunked the switches, and modes they are in, I'll walk through the changes step by step as I introduce the nuke switch. Advertisements / "Subset Advertisements" and Configuration Revision # Now as previously stated, the highest "Configuration Revision #" in a VTP Domain is considered … Continue reading VTP – Intro to Advertisements and Config Revision #, DEEP DIVE into Cisco “VTP synch issue” and Cisco’s official fixes for it – Important!
OSPF Summarization is done only on ABR and ASBR routers in your OSPF domain, and use two completely different commands, but what if a router is an ABR and an ASBR? For example, did you know that using the command "default-information originate ..." you are telling the router to create a Type 5 LSA to … Continue reading OSPF: Important details regarding Summarization and Default Routes for exam day, it’s a long but worthwhile read!
I pulled this topology from my older posts when I took a deep dive into the world of LSA's, how to read the Topology table like a laundry list and under stand it, and what type of routers did what. First I want to list links that are absolutely vital to read and understand for … Continue reading A collection of IMPORTANT links to review and know for exam day, then a quick overview of LSA Types / OSPF Router Types!
Only the NBMA and Ethernet segments will be used for quick demonstrations and clarity, unless R4 or R5 is needed for demonstration. The first mechanism specifically for EIGRP to filter EIGRP learned routes is by distribute lists, which have a similar syntax structure and function in ways as an offset-list, in the ways that: It … Continue reading EIGRP: DEEP Dive into Route Filtering with Distribute-Lists using ACL’s – Important notes on using Extended ACL’s for exam day!
Let me preface this by advising you write some sort of version of this chart on your dry erase board before beginning the exam, so you are not scrambling to remember it while the clock is ticking down during the exam, and if you don't understand this chart read about it below until you do! … Continue reading Important Subnetting review to quickly find network address, ranges, and a great “cheat sheet” for exam day!
Directly from Cisco's website: 1.1 Identify Cisco Express Forwarding concepts 1.1.a FIB - Forwarding Information Base, "sh ip cef" to view, used to determine next hop IP addresses, performs Layer 3 "Packet Switching" or Packet forwarding 1.1.b Adjacency table - Correlates with FIB to find corresponding MAC addresses for Packet Switching / Forwarding Both these … Continue reading ROUTE Blueprint “Network Principles” section topics all covered within this post (briefly, but covered)!
So this is very odd to me after going through the last two posts of GRE and IPSec configuration, however once I found good information, configuration was a breeze. **PLEASE READ EXAM DAY NOTE AT END OF POST FOR SCENARIOS WHERE THE ROUTES HAVE TO BE IN THE DYNAMIC ROUTING PROTOCOL FOR OTHER ROUTERS** You … Continue reading VPN: DEEP Dive into GRE over IPSec configuration, explanation, and very easy actually once you are familiar with GRE and IPSec!
This first image is a break down of the different types of VPN Packet Type by the headers / trailers (or lack thereof), and the following of your typical IPSec VPN Packet Type: The VPN generic representation of the IPSec VPN Packet above works for a general review, but there are details in the headers … Continue reading VPN: DEEP Dive into different VPN Packet Types, Packet Headers, and the differences between VPN Packets and their Modes!
One thing that was lacking from Chris Bryants training that I found in the INE series is explanations between when to use OSPF Filter-list vs a Distribute-list. I have modified the network as reflected in the Topology so Area 34 will no longer be a stub, and Area 15 will only be an NSSA Area. … Continue reading OSPF: DEEP Dive – Distribute-List vs Filter-List, and reviewing Prefix-Lists as Filter-Lists use Prefixes to filter!
Since I already have the lab configured with different OSPF Area's, and we had a riveting exploration into the world of LSA's and the LS DB of each router, I wanted to hit some other topics again thoroughly before I switch up protocols for more DEEP Dives into all things CCNP ROUTE related! Without further … Continue reading OSPF: DEEP Dives into Summarization methods, Authentication, Default-Information Originate (Always)!
To lead off where we left, we made Area 15 an NSSA Area which stopped the Type 4 and 5 LSA's from entering the Area, now we are going to do some Redistribution the other way and turn R5 in the NSSA Area into an ASBR. I've created networks (loopbacks) 220.127.116.11 /32 and 18.104.22.168 /24, … Continue reading Part 3: OSPF LSA DEEP Dive LSA Type 7, DEEP Dive into OSPF Stub and NSSA Areas, and how they impacts LSA traffic!
I will start this off by stating that we will start redistribution on the ASBR specified R2 to examine LSA types 4 and 5 (and where we can spot them), and R1 will eventually also be turned into an ASBR when we redistribute some loopback routes into the NSSA Area so we can review type … Continue reading Part 2: OSPF LSA DEEP Dive, LSA Types 4 / 5, and turn Area 15 to an NSSA to see what happens with the LS Database!
So we are back to OSPF, as I never really went into a deep dive with LSA types, or the LSA DataBase from different routers to show their perspective of the OSPF network caused by these Link State Advertisements. I've only configured base OSPF and RIP configurations in this lab so far, the above Topology … Continue reading Part 1: OSPF LSA DEEP dive, starting with LSA Types 1 / 2 / 3, and an Intro to all LSA Types and OSPF Routers types!