Skip to main content

Route This Way: Introduction To Routing Protocols + RIP

Less 'introduction' and more "Well, I paid and studied to take the CCNA, so I'm going to put this information to use somehow."




Also, apparently network administrators feel very strongly about their routing protocol of choice, and will fight people over it.

To be clear, I'm 🤔 at the person who went through all that effort to make an account to do this. I have that kind of time as well, but I'm not doing that, I'm doing this.


So, what is a Routing Protocol?

Graphic Design in My Passion

Routing protocols do a lot of the configuring for you on a network. No need for incessantly typing in static routes, which don't scale easily across a large network and take up a lot of time.

Distance Vector -
  • How far away is the destination. This is usually counted via hops.
  • Slower convergence because it sends the entire routing table.
  • Prone to loops.

Link State -
  • The router knows about every other router and it's, well, link state. 
  • The only information that is sent or received is changes in links - are they up or down?
  • Converge much quicker, at the cost of using more CPU.
  • Has three tables:
    • Neighbor - "Who's running the same routing protocol?"
    • Topology - "Where is everybody?"
    • Routing  -"How can I get to this place quickest?"
Let's start with RIP, so this post isn't woefully short:


Here is the topology so far; The following configurations are focused on the highlighted bits.



Configuration is simple:

I don't recall version 1 being used...a ton - or at all in the learning present day - so we're going with version 2.


Everything in the 192.168 and 10 networks are being advertised to Router 2 (on the left).

 show ip route



The 10 and 192.168.1 networks are 'directly connected', as they're on the same router where I ran the command.

Let's set up Router 2 (on the left) and show ip route again on router 1.


The highlighted area says "Yes, we're connected with the RIP routing protocol.". We can also stop the PCs from receiving RIP updates with the passive-interface command within the routing protocol configuration:

passive-interface [int]

 This network is small, so the 15 hop count limit that plagues RIP will be no issue here. But what if the network was far bigger?

Keep reading.

Comments

Popular posts from this blog

Connecting IoT Devices to a Registration Server (Packet Tracer, Cisco)

In Packet Tracer, a demo software made by Cisco Systems. It certainly has changed a lot since 2016. It's almost an Olympic feat to even get started with it now, but it does look snazzy. This is for the new CCNA, that integrates, among other things, IoT and Automation, which I've worked on here before. Instructions here . I don't know if this is an aspect of "Let's make sure people are paying attention and not simply following blindly", or an oversight - The instructions indicate a Meraki Server, when a regular one is the working option here. I have to enable the IoT service on this server. Also, we assign the server an IPv4 address from a DHCP pool instead of giving it a static one. For something that handles our IoT business, perhaps that's safer; Getting a new IPv4 address every week or so is a minimal step against an intruder, but it is a step. There are no devices associated with this new server; In an earlier lab (not shown), I attached them to 'H

Building, Breaking, and Building A CRM with Retool

 I like no- or low-code solutions to things. I've often wanted to simply push a button or move some GUI around and have the code implement itself.  I've thought about building something that's like a customer relationship management (CRM) system for keeping up with my network better than my little spreadsheet where I click links and then go like something. The general idea in this CRM Development is:  To have a GUI to add people to a NRM (Network Relationship Management).       Attach it to a database (MySQL is what I went with eventually using Amazon Relational Database service, but you can use PostGRES, and probably others).     Make sure components are connected to each other in the retool interface. This video is a good start. Watching the tutorial video, heard some SQL commands and went 'Oh no 😳" before going "Wait I know basic SQL", which is good, because you'll see.  When you get set up, there's a plethora of resources you can use -- Incl

Securing Terraform and You Part 1 -- rego, Tfsec, and Terrascan

9/20: The open source version of Terraform is now  OpenTofu     Sometimes, I write articles even when things don't work. It's about showing a learning process.  Using IaC means consistency, and one thing you don't want to do is have 5 open S3 buckets on AWS that anyone on the internet can reach.  That's where tools such as Terrascan and Tfsec come in, where we can make our own policies and rules to be checked against our code before we init.  As this was contract work, I can't show you the exact code used, but I can tell you that this blog post by Cesar Rodriguez of Cloud Security Musings was quite helpful, as well as this one by Chris Ayers . The issue is using Rego; I found a cool VS Code Extension; Terrascan Rego Editor , as well as several courses on Styra Academy; Policy Authoring and Policy Essentials . The big issue was figuring out how to tell Terrascan to follow a certain policy; I made it, put it in a directory, and ran the program while in that directory