Study Session Number 5! RIP, EIGRP and OSPF! #6

Hi Everyone! 

Today I decided that I was going to brush up on my routing protocols - RIP, EIGRP, OSPF, IS-IS.

RIP used distance vector, so does EIGRP although its better its not ideally suited for businesses. OSPF is the most widely used protocol as its vendor neutral and is link state. IS-IS is a protocol aimed at more at ISP's. 

Interior Gateway routing protocols - RIP, EIGRP, OSPF, IS-IS.
Exterior Gateway routing protocols - External BGP.

Link state - Makes decisions based on the cost of the link (internet speed).
Distance Vector - Based on how many hops to X devices. 

Administrative Distance - Lowest AD to route wins. AD is how much that link is trusted.
AD Measurements - 
Connected - 0 
Static Route - 1
External BGP - 20
EIGRP - 90
OSPF - 110
IS-IS - 115
RIP -120

Metric - 
When multiple paths are learned through a routing protocol the metric will be used to decide what path is the best along with the AD.

Router looks at AD first, then uses metric to decide what path to use. 

[120/1]
120 = AD (RIP)
1 = METRIC

Floating Static Route - 
The route essentially "floats" in the background as a backup link, the AD is modified to be higher so that the route will be chosen second to the other route that has a lower AD (lower is better).

Loopback Interface - 
A loopback is a logical interface that isn't locked down to a physical interface - because of this the interface can never fail. A loopback uses a /32 subnet mask as it cant be put into the physical address space and also uses an IP address (basically a standard IP address but uses a /32 subnet). Loopback is useful for Voip traffic and as a management interface.

Passive Interface - 
A passive interface is configured to send out routing updates to a network, the routers will learn how to get to the passive interface but wont send out updates to it. Used for loopback interfaces and networks that might need access in future. 

RIP - HOP COUNT (RIPv2 - Uses Multicast address to send updates, 224 address. Max hop count = 15)
EIGRP - BANDWIDTH/DELAY
OSPF - BANDWIDTH/LINK COST

RIP is aware of neighbors, OSPF is aware of the whole network, an easy way to remember this is to think of when RIP is used on a router it has a Point Of View perspective whereas when OSPF is used its a birds-eye view of the network.  
 
Will go into more depth in different blog about EIGRP & OSPF.





Comments

Post a Comment

Popular posts from this blog

Python Crash Course Chapter 1-2! #1

 Hi Everyone,  As a continuation from my CCNA I have started studying towards my Cisco DevNet, to do this I need some prior knowledge with Python (which I dont have) so after doing some research I have found this book! I will be using this until I am comfortable with Python.  In the first two chapters I have learned how to create variables and assigned them values, along with this I have also learned how to use methods with the variables. These are some examples of me beginning my Python journey -  blog_message = "Hi everyone! My name is" name = "Iain" first_blog = "this is my first blog about Pyhton, enjoy!" day, month, year = 29, 11, 2020 print(f"{blog_message.title()} {name.upper()} {first_blog.title()} {day, month, year}") This is my first piece of coding, in this I got to use variables, methods and integers. 
Read more

I PASSED! Cisco CCNA 200-301! Experience & Where I'm going from here!

 Hi Everyone, Long time no see. As the title says - I passed! After all the studying I have finally finished my CCNA on November 27th. So as a summary I managed to score 900/1000 - what do I think of the exam? I think that the exam focuses on a much wider spectrum than just R&S, I had an illusion in my head that most questions on the exam would revolve around R&S protocols when this wasn't the case at all! I had a majority of wireless questions is regards to WLC's, AP's etc (without going into to much detail - sorry guys blame the NDA) along with this there was other things that were involved that weren't on the blueprint which was mildly frustrating. My Advice? Learn all the gritty details, learn how to read routing tables things like longest prefix, AD, metric - what path will win? Learn protocol numbers, what the requirements for that protocol are to make a decision e.g how HSRP uses an active and standby router and how it decides what router is doing what. B
Read more

Python Notes #6 Functions

 Hi Everyone, Today I'm doing functions I have kept this as its own blog as this is a bit of a tougher topic and for my own memory I'd like to be able to find this easily if I ever had to review python notes. A function is a chunk of reusable code this means that the code can be created and then passed anywhere within the code later on. This is how a function works -  def name(first, last): print("Please enter name: ") print(f"Your name is: {first} {last}") name("Iain", "H") In this chunk of code I pass the parameters first & last within the function - from here I create a print statement asking for my name, notice how in the second print statement I am passing the parameters first and last (represented by the curly braces) and lastly I call the function name and define the values within the brackets - with the last statement now first will = 'Iain' and last will = 'H'. This code produces this output - Please enter
Read more