Question basic network design question-done subnetting, have solutions, just want ideas?

[shivajikobardan]

Design the redundant network for Purdue University with 4 departments including ISP which are around 300m apart from each other. Three departments have 4 labs each with 24 computers in each room . ISP contains server farm with server like DNS, DHCP, Email, FTP, NMS(wtf is NMS), and webserver and the main internet router which will be connected to upstream provider. Propose appropriate equipment(L1,L2 and L3) and physical wires for the network design.


here are the files of solutions, i have read and tried to understand all of them. i have understood subnetting. i have understood network design as well, but even though i am dumb, i can tell that most of the network design drawn here is wrong. so i am asking this question here, hope to get help.

https://file.io/m2WVY3Bd1VkX

backups-:

https://fromsmash.com/pdfsolution

(tell me if there is a good site to share these stuffs w/o signups).

The question is clearly asking me to design the 3 layer networks i.e distribution, core and access layer. And some of the questions ask to be redundant. The problem is I have seen a whole book on redundant network design and not just few guidelines that would help me in this small topic of my course. (The topic weight is just 8% of the entire final exam). I love reading and would definitely read 1000 pages of top down network design sadly there are restrictions in real life. It would take me 3-6 months to finish that book all on my own.


so here's the subnetting solution-:

let's take ip address 192.168.0.0

total required hosts=294

2^x-2=294=> x=7

/## will be /25

D1-:

192.168.0.0/25 - 192.168.0.127/25 (I will only keep network address-broadcast address here, rest can be found pretty easily from it)

D2-:

192.168.0.128/25-192.168.0.255/25

D3-:

192.168.1.0/25-192.168.1.127/25

ISP-: ( I took number of hosts as just 6 although it says ISP contains a main router. Should I consider a router as a host? Or is it different? My books don't consider it as a host. Isn't router just a computer? thus a host?)

192.168.1.128/29-192.168.1.135/29


now there are lots of questions.

for a moment, forget the redundant network design.

forget the L1,L2,L3 design,and let's do a basic level design.

https://imgur.com/a/Ya9uVDH

View: https://imgur.com/a/Ya9uVDH



This is the stupid design I made.(of I know this is not real n/w)

D1 means department1.

L1 means lab1.

*24 means 24 hosts

*6 means 6 servers

the one is ISP is main router.


what the answer according to my book(it is very unauthentic book with plenty of mistakes, depending on that book to learn sth is a learning suicide, it's not written by any reputed professors. This book is a huge scam in our university where they don't teach anything in classes, don't help students so that we buy these books. And isn't even written by best quality professors. Tbh best quality professors never stay in our country, they just get opportunity to move abroad.)

1) Main router-:

a) router for D1(that uses network address)===> switch1--->24 hosts

b) router for D2====>switch2===>24 hosts

c) router for D3===>switch3===>24 hosts

d) router for ISP===>switch4===>6 hosts

is this correct? if this is correct, could you give a small explanation of this system? i feel this is correct. but why are we using another router in ISP when ISP already has main router? a brief explanation would be helpful.

now say I want to make this design redundant.

I make everything two times. would not that work lol?

The devices required will be-:

1) Main router

2) Switch

3) Optical fiber

4) CAT6 cable

5) Laptops

6) Servers

7) wireless router (why and where is this required? any ideas what use this will have here?)


Hope to get help. This is a long question but the answer to this is short as I am just asking that n/w design part. And we don't have to make networks in laptop, we just need to design in theory.

 

[bill001g]

So what restriction do you have placed on you.

The solution used by actual real business is to make the solution simple to support rather than have the most efficient solution. Nobody really cares about private IP addresses. Almost no company other than the ones that got huge blocks 20 years ago use actual public IP addresses for their devices and even then they are really used as private IP since they never allow direct access between these internal IP blocks and the internet.

The way this is done for real is to just use /24 blocks for everything. You have so many you can use out of the private block and even if you run you then start using the bogan networks or ones allocated to millitary that are never used on the internet.

Even on the internet things don't work the way they talk about in books. They want to use every IP including the ones you normally allocate to broadcast and network. They do tricky things like assign a /32 loopback to devices and have the devices talk to each over a private network and use routing protocols to keep track of where all the public IP really are.

If you are looking at the education methods your assumptions are mostly correct. You need to take the total number of addresses in a subnet less 2 and then assign IP to every device including the router/gateway from the ones that are left.

 

[nigelivey]

Homework?

 

[kanewolf]

Design the redundant network for Purdue University with 4 departments including ISP which are around 300m apart from each other. Three departments have 4 labs each with 24 computers in each room . ISP contains server farm with server like DNS, DHCP, Email, FTP, NMS(wtf is NMS), and webserver and the main internet router which will be connected to upstream provider. Propose appropriate equipment(L1,L2 and L3) and physical wires for the network design.

...

The question is clearly asking me to design the 3 layer networks i.e distribution, core and access layer. And some of the questions ask to be redundant. The problem is I have seen a whole book on redundant network design and not just few guidelines that would help me in this small topic of my course. (The topic weight is just 8% of the entire final exam). I love reading and would definitely read 1000 pages of top down network design sadly there are restrictions in real life. It would take me 3-6 months to finish that book all on my own.

First thing I see in the assignment is "redundant". I don't see that addressed.
I don't see a REQUIREMENT for any isolation between anything in the description. Is layer3 required or is this a big layer2 network ?
There is no REQUIREMENT for WIFI. Adding anything WIFI is outside the scope of your requirements. Your competitive cost would be much higher than your competitors that stuck to the requirements.
It really depends on if you are trying to bid this design to win or if you "think you know more than the customer" and believe you should "fix" the deficient requirements.
If this were an RFP (request for proposal) you would use your question period to ask about things you believe are omissions in the requirements. Things like racks or power distribution, or if you are required to pull the fiber between buildings, of if there is already trunk fiber between buildings.