Need some advice on learning networking

[BillyCarpenter]

Re: Need some advice on learning networking

This is really getting interesting now. Lets see how I can explain it....


If you're reading this, the data you see has gone thru several routers to reach your PC. There were multiple router paths the data could have taken but it chose a certain combination of routers to reach your PC. How were these routers chosen?

The answer to that question is one that I can't answer fully because I haven't learned Dynamic Routing yet. But I can tell you this: there are several Dynamic Routing Protocols. Each one of those protocols will look at things like "Shortest Path First" or "Administrative Distance", ect.

At the moment I'm still building static routing tables but this time I'm using "Route Summarization" and I'm learning to teach the router to take the path that I want it to take. Still work to do to fully understand it. I'm getting close.

[BillyCarpenter]

Re: Need some advice on learning networking

I started studying Route Summarization yesterday. If feels like I've been on it for 5 years. Oh, I got the "formula" down right away thanks to my knowledge of subnetting but that's only a very small piece of the puzzle when it comes to actually implementing and understanding Route Summarization.


I've probably logged 12-hours of study time strictly on Route Summarization. Trust me, that's a long time.

Everything about CCNA is broken down into topics. I equate each topic as a battle in a war. You go in ready to fight. You take some incoming fire. You get tired and weary but somehow press forward until you win that individual battle but over the next hill a new battle awaits. I think I've won the battle on Route Summarization. I think I'll take the next 24 hours off and get ready for the next battle.


Oh, by they way, Route Summarization is really cool. It cuts down greatly on the number of routes that I have to manually enter into a router and it uses less memory in the router and the network runs faster as a result of not having so many routes in the routing table.

[BillyCarpenter]

Re: Need some advice on learning networking

I wonder how many folks have actually studied routers?

I'm not talking about in a home setting or small office environment. I'm talking about on an enterprise level. This takes some special knowledge.


Here's the best way that I can describe routers on an enterprise level: The internet was invented by the military as a means of communication in the event of a nuclear war. If communication lines were bombed in one area, data would automatically be rerouted and would reach the intended destination. In other words, if a single line went down, there were alternative paths for the data to travel down.

Think of an enterprise setting along the same lines. These multi-billion dollar companies can't lose connectivity. It's important that their network stay up AT ALL TIMES. One way of making sure that happens is to design a network with multiple routers, with multiple paths in case 1 router goes down. The problem is that you can't just hook up a bunch of routers and expect them to automictically know how to route traffic. This requires a certain level of expertise to design and configure. And it's more complicated than I ever dreamed.


PS - Redundancy is also true for switches but I'm only talking about routers right now.

[copytech,mike]

Re: Need some advice on learning networking

I have had 2 customers where scan to email was not possible due to concerns over corporate espionage concerns. One was a petroleum construction company. The other was the west coast proving grounds ground for Hyundai/Kia. Hyundai/Kia even had me disable scan to memory devices.

Sell them a Konica Minolta! In a pinch (scan to email can be a bitch to get to work) you can set them up for scan to user box in about 3 minutes! Love the Bizhub! Scan to Desktop is basicaly obsolete. Its a real pain to set up and has serious security risks these days. Worse risks than email. Im in the same boat as you. I learn a little here an a little there. Took me ten years to finally get scan to email to work!

[BillyCarpenter]

Re: Need some advice on learning networking

The CCNA course that I'm taking can be found at: Online Courses - Learn Anything, On Your Schedule | Udemy

I highly recommend Udemy. I also highly recommend everyone to take this course. Doesn't matter how old or young you are. I strongly believe that a good copier tech would make a good networker. That's especially true if you pay close attention to every detail. In today's world, knowledge is money, so why not further your education?

With that being said, there are a couple of course on Udemy for CCNA. One is taught by David Bombal. He teaches hands-on learning where you actually program the switches and routers. That's the one I started with first. I was able to jump out pretty quick to some more advanced stuff, however, it didn't take long for me to realize that there were some major gaps in my learning.

That's when I decided to sign up for a 2nd CCNA course that dealt more in theory. One of the smartest decisions I made in a while. This has definitely filled in the gaps...and more!!!

This 2nd CCNA course is taught by Neil Anderson. He's been fantastic.

It should be noted that even though Udemy does a great job that I've still had to seek out more information in books and on the web. You could probably pass the test without doing this, but there's some great stuff on YouTube that has really helped me along the way.


Next week, I'll finally start on Dynamic Routing. I've been chomping a the bit to get to that.

[copytech,mike]

Re: Need some advice on learning networking

When I was learning to set up scan to PC I couldn't get it to work. Keep in mind I had never done it before. After a few long hours of frustration, I discovered that SMB was off. Major headache. I've run into so many unexpected problems in the field with things like firewall settings, router settings that need to be changed, ect. Not to mention crappy networks that weren't set up right.

I'm not looking to be a network guru but I believe that knowledge is power and the more you have the better. I like to sound and feel knowledgeable when I'm talking to an IT person or customer. Right now I don't feel that confident that I can fix a problem should it pop up.

i UNDERSTAND. I have been thru it. You can watch some You Tube Videos on Scan to SMB and Email by typing in keywords like, Bizhub C308 scan to email set up. Prestige office solutions has several awesome you tube videos that will help you. They are there for newbies. Good Luck! -Mike G.

[BillyCarpenter]

Re: Need some advice on learning networking

I really didn't; know what I was getting myself into when I signed up for this routing and switching course. I don't think anyone knows what they're getting themselves into when they sign up for the course. Not really.


There have been times where I've asked myself if I was smart enough to learn this stuff. It can be really complicated and there's a mountain of information to learn. It can be overwhelming.

Here's the good news.....

As long as you don't give up, things will start to settle down. Light bulbs will begin to come on and it'll start to make sense. Above all else, trust the process. Learn the course in the order that it's given to you. Don't jump around. That's a big no-no.



I'd like to share something before I end this post:

In networking, everything is about "rules". In networking "rules" are referred to as "protocols." When you read "protocols", it's just another word for "rules." You can't play the game until you know the rules. The "game" in this case is "routers" and routers have rules. Once you know the rules, you can make the router do what you want them to do. And it's pretty amazing what you can get them to do.

Let me give an example of one of the rules in routing.....

Lets say that I enter the following 2 routes in the routing table:

ip route 10.1.0.0 255.255.252.0

ip route 10.1.0.0 255.255.255.0


The first route that I entered (10.1.0.0 255.255.252.0) is a summary route.

The 2nd ip address that I entered is a direct static route (10.1.0.0 255.255.255.0)

It's not important whether or not you understand the difference between the 2 routes. What is important is to understand the rules:

The rule is this: The longest prefix wins.


10.1.0.0 255.255.255.0 has the longest prefix thus that's the route that will be chosen.

Longest prefix match (also called Maximum prefix length match) refers to an algorithm used by routers in Internet Protocol (IP) networking to select an entry from a forwarding table.[1]





For example, consider this IPv4 forwarding table (CIDR notation is used):


192.168.20.16/28
192.168.0.0/16
When the address 192.168.20.19 needs to be looked up, both entries in the forwarding table "match". That is, both entries contain the looked up address. In this case, the longest prefix of the candidate routes is 192.168.20.16/28, since its subnet mask (/28) is longer than the other entry's mask (/16), making the route more specific.


Forwarding tables often contain a default route, which has the shortest possible prefix match, to fall back on in case matches with all other entries fail.

[BillyCarpenter]

Re: Need some advice on learning networking

It's becoming harder to share my progress and that's because the concepts that I've learned are more advanced and thus wouldn't make any sense to anyone who's never studied routers to this degree.



When I first started this thread many months back, I knew NOTHING about routers or switches, or even computers. It was all a mystery to me. Knowing what I know now, I honestly wonder how many people truly understand routing on a production level. I wonder who could actually explain how routers forward packets across the different networks?

Currently I'm working on Dynamic Routing Protocols. This is a breath of fresh air. I'll give an update on those in the next couple of days.

[BillyCarpenter]

Re: Need some advice on learning networking

Someone may find this interesting. Or not. Either way I'm gonna share.


Imagine a network at a college campus. Now imagine that there's 20-30 routers that separate all the individual networks. And there's a couple of edge routers that connect to the internet.

In order for connectivity to be possible across the different networks, "routes" must be entered in the "routing table." There's 2 ways to accomplish this:


1. Static Routes. (Manually entering.)
2. Dynamic Routes (A routing protocol is used. Routing tables are built without help from an administrator.)


I learned all about building static routes for a network with hands on experience. This is time consuming and the level of difficulty is high. It's also not scalable. The experience taught me a lot. The knowledge gained is invaluable to networking.

But now I'm on Dynamic Routing Protocols. There are about 4 protocols that are used. Each one is different than the next but all accomplish the same goal.


One protocol only takes into consideration how many "hops" need to be taken to reach the destination. The route with the least amount of hops will win and thus be entered into the routing table. Sounds great, right? Well, there's a problem with that. This protocol doesn't take "bandwidth" into consideration. So, while it may have the least amount of "hops", the lack of bandwidth may make it a slower alternative to a route with more hops but has a higher bandwidth.

Did anyone follow that?

[BillyCarpenter]

Re: Need some advice on learning networking

Who wants to learn about the "gateway of last resort"?


Let's say that we have a topology that consists of the following 4 networks:


1. 192.168.1.0/24
2. 192.168.2.0/24
3. 10.0.0.0/24
4. 10.0.1.0/24


Lets say that all the networks are divided by a router. In order for us to have connectivity between the 4 networks, we must configure 4 routes on all the routers. That's great, now we can communicate across all 4 networks.


But how do we get out to the internet? How to we get to google.com that has an IP address of 8.8.8.8 ?

We must configure the following IP route on ALL of the routers: 0.0.0.0 0.0.0.0 ---- This is our gateway of last resort. Basically all the 0's tell the routers to forward any unknown IP addresses to the edge router...which is connected to the ISP router.


Now you know.

[BillyCarpenter]

Re: Need some advice on learning networking

When you get into production networks, there will be multiple paths to reach the same destination (i.e., your computer). In other words, fault tolerance is built in. That's where Routing Protocols play a big role.


There are competing routing protocols:

a). OSPF
b.) EIGRP
c.) IS-IS
d). RIP

All of these routing protocols have one thing in common: they all advertise their routing tables to the other routers in the network. From there each router decides for itself what's the best route to take to get to a destination. Moreover, if a link happens to go down, the router will delete that route from it's routing table and build a new link if one exists. In other words...it's self-healing.

That concludes today's update on Dynamic Routing Protocols.

[BillyCarpenter]

Re: Need some advice on learning networking

Yesterday I put in about a 10-hour intense study session on RIP (Routing Information Protocol). I can do the long study sessions but it really takes its toll mentally. I'm not as young as I used to be.

Anyway, while RIP isn't really used anymore (except in small networks), the fundamentals behind RIP are important to learn. Once I learned the fundamentals, I had to go to the virtual lab and verify what I learned. It's intense learning. I can promise you that. CCNA goes very deep on these topics. I can see why 90% fail the CCNA test on the first attempt. It's really not about memorization, it's about understanding how it all works and troubleshooting.

Basically RIP only takes the number of hops into account when building it's routing table. That's a major flaw and the chief reason it's not used. Other routing protocols such as OSPF are more commonly used. OSPF takes "bandwidth" into consideration when deciding the best path to take. It's much more efficient.


Last but not least:


Routers use RIP and OSPF to build a routing "database". This is not to be confused with a routing "table". The "database" is a complete list of all the routes in a network. The routing "table" is a list of the BEST network paths and these are the ones that will be used. If a link goes down, that route will be deleted from the routing table and replaced by a slower route from the routing database.

Hope that made sense.

[blackcat4866]

Re: Need some advice on learning networking

...

Hope that made sense.

You lost me several pages ago. It's still interesting reading though, thanks. =^..^=

[tsbservice]

Re: Need some advice on learning networking

You lost me several pages ago. It's still interesting reading though, thanks. =^..^=

Shame on me. +1 BC said.

[BillyCarpenter]

Re: Need some advice on learning networking

You lost me several pages ago. It's still interesting reading though, thanks. =^..^=

It would be a huge time commitment, but I think you're the type of person that would be great at networking. Just judging by your work ethic/habits, this would be right up your alley.