"We are designing a new workspace with 3 floors. On average, there will be 100 devices on each floor that require wired and wireless connectivity. Submit a network design including: (1.) A network diagram (2.) Hardware choices (3.) VLAN and subnetting information (4.) Anything else you think is relevant."
This was a question for a position at Shopify. While it was publicly available, I decided to wait and post this when the position closed.
Break it into chunks. Separate it by something, in this instance, the floors.
Determine the departments.
Subnets per floor - I'm not using CIDR.
Pick the hardware.
Ask other questions.
This company uses Juniper and Aruba products. As you've seen, Juniper is far easier to get started with. I tried using Cisco DevNet for automation work without using a Linux machine to remote into it - Absolutely arduous.
FOR EACH FLOOR:
EX9200 Switches - 120 ports, to account for growth.
Shopify handles business proceedings and gives online shops a web interface, but what would this department specifically be doing? There's some cloud database somewhere else handling those transactions, not these people.
Without that information, I'm accounting for potential growth and suggesting a MX10.
AP33 Juniper WAP - Remember backwards compatibility. We don't know how old some of these nodes will be that are coming onto the network.
Which medium - Wired or Wireless - Would the devices be using the most? With my laptop, if I connect it via Ethernet cable to my router, it will only use one connection or the other - It won't use Wi-Fi and Cable at the same time.
This Juniper firewall is an on-prem appliance. You may not want the extra physical appliances and opt for a software firewall package for all of your nearly 300 end points. As this encompasses the entire network - think drawing a circle around a network and calling it a firewall - consider it.
Since the machines need both wired and wireless, let's make them all laptops. That means they need an Ethernet port - Like this Lenovo Thinkbook.
Will they be using IP Phones? Network printers?
VLANS and SUBNETTING
There are no instructions as to how the systems will be organized, so that means I can do as I like! Let's assume that the 'average' of 100 devices means 100 or less.
FLOOR 1: 94 Devices
29 - Sales
25 - Help Desk
5 - Food and Beverage Stations (Think purchasing at a company cafeteria. Imagine they use Square devices.)
20 - Copywriters
20 - Secretaries
Subnet Bits: 3
Max # of Subnets: 8
Hosts per Subnet: Want to minimize the addresses in them to prevent waste, but things don't fit so neatly in the real world.
Mask Bits: 27
Hosts per Subnet: 30. We could possibly make more subnets and dictate them as "Sales1" and "Sales2" for instance, as to not absolutely push the limit, and the amt of hosts in each would be lessened.
FLOOR 2: 90 Devices
30 - Marketing
30 - Meme Makers
30 - TikTokers
This is a little easier, because we can assume that there will be more people added to the Marketing or TikTok VLANs, so I feel better regarding more hosts per subnet here.
Max # of Subs: 4
Subnet Bits: 2
Mask Bits: 26
Hosts Per: 62
FLOOR 3: 99 Devices
40 - Customer Support
55 - HR
4 - Level 3 Techs
I'm okay with breaking departments into multiple subnets here. With 30 hosts per subnet, there's growth allowed for each department. There can be 2 for CS and HR. Level 3 techs wouldn't need 2 subnets of 30 hosts unless they hired some more people.
Max # of Subs: 8
Subnet Bits: 3
Mask Bits: 27
You could also account for growth with 4 Subnets of 62 hosts per subnet, but that's too much for L3 techs, even accounting for growth.
Assume that all devices are reaching an internet and an intranet. Do we need other machines to host internal pages and files?
Do some departments need more of those resources than others? For example, should Sales and Help Desk get more throughput than HR?