Redundant network design and how it affects subnetting?

[shivajikobardan]

Considering these factors, propose a redundant network design architecture in hierarchical form for a bank having four departments namely HR(20 pcs), marketing(20 pcs), finance(45 pcs), IT (30 pcs). Each department has managed its own DHCP server. IT department has managed FTP server, HTTP server, and DNS server as well. Use suitable L1,L2, and L3 devices, physical wires, patch cords, patch panels and wireles access points.

A) Requirement analysis-:
HR=20+1=21
Marketing=20+1=21
Finance=45+1=46
IT=30+1+3=34

B) Components required-:

=> What does L1, L2 and L3 signify here? I bet they’re trying to say about core, distribution and access (they could be saying about physical, data link and network layer as well but that’s unlikely as they’re talking about “L1,L2,L3+physical wire”)

C) Subnetting-:
Major network ip address=202.53.69.0/24

https://lh3.googleusercontent.com/gqB46PqT0D_0d54fPPHXlvhW7k_QqhtQMaShRkGTOyYY1B82uDUJuOonyn9W4tve1-m-loTC9mhbMmzqyDmidea3iA8aeKkrGqC_OCIDW_7wJSgUHDbw3ROca9SEFtwumTFZYnTjHIwTVdNsf-k

D) https://lh3.googleusercontent.com/J50bwl6nB1yvhuy0AgF2laeyUct2QH8of1RwsA7yl7HjsyIyLacTePl3QE481BrapTMwADE0ko_l_jABhE_9gJXV5e-_RHnBeX-NopBM2FUYzcMkdXYgyKMTnKFCOcXhmk9GruuUqh0idXfsEdc

This is the network. But ofc this is not redundant.
1) What are the basic things that I should do to make this redundant?
=> the below figure is pretty redundant and cost effective imo. It looks good like core, distribution,access as well.
https://lh6.googleusercontent.com/YIP9uV6V6aB5ub-51oWfoSAs71U2Wb3W9FHvazvyU6Arrn7i49WNokd_m5RlRMgaT9v2yZsWdjBqPER1_YiyuFnrAs0BW4lT6vR6nM6SAM7teYkpdiARDOWkGWEDiR1JhDFZ9q2HGgp9Z7F1Db8
You could propose your own design and ignore mine.
How do I manage subnetting for redundant design? Or should I ignore it? What I am saying is since there are 2 switches, I need 2 ip addresses for them. I think I need the ip address to be unique each switch. Similarly for 2 core routers, I’d need 2 different major network ip address.

How’d that affect subnetting?

 

[Future Bruno]

=> Subnetting is still applicable in a redundant design. In this case, you would need to assign two separate subnets for each of the switches, core routers, and DHCP servers. You would also need to ensure that the subnets are not overlapping. For example, if the major network IP address is 202.53.69.0/24, you could assign two separate subnets as 202.53.69.0/25 and 202.53.69.128/25. The first subnet would be used for the switches, the second subnet would be used for the core routers, and the third subnet would be used for the DHCP servers.