How does subnetting affect network topology specifically routers switches hubs etc?

Subnetting is the key to network topologies....

i wount go into details but will explain in simple example which makes sense...

you network in 172.16.0.1 subnet mask 255.255.255.0 i.e 172.16.0.1/24 24bit mask

the subnet mask 255.255.255.0 shows that you can have max 254 hosts the last 0... 254 and not 255 as the last IP is always for broadcast.. so available hosts will be always last octave -1

you will be able to ping and access all hosts in this 172.16.0.1-254 range..

but if another network is of 172.16.1.0 range you will not be able to access it from 172.16.0.1 network, either you will require router to route the traffic in network or... increase you subnet range..this different

so to access 172.16.1.0 network from 172.16.0.1 change subnet to 255.255.254.0 both the networks will be available now.

so it translate to..

255.255.255.0 = 254 hosts

255.255.254.0 = 254 hosts + 1 more network

you have 172.16.0.1-172.16.1.254 hosts available

255 networks + 255 networks + 255 networks + 254 hosts

each single digit has 254 hosts...

therefore

255.255.254.0 = 254 hosts + 1 more network becomes

172.16.0.1 from 255.255.255.0 254 hosts

172.16.1.0 from 255.255.254.0 254 hosts + 1 network

range extends from 172.16.0.1 to 172.16.1.254

so similarly is you want your network to be of less hosts you you can modify your subnet to do so..

if you want to have 14 hosts in you network then

172.16.0.1/28 28bit mask subnet mask 255.255.255.240 you have 14 hosts 172.16.0.1-172.16.0.14

when internet service providers give you IP addresses they give you like this

your WAN ip: 67.67.1.1

gateway: 67.67.2.3

LAN IP: 68.3.2.1/29

here you have 29 bit mask, subnet mask becomes 255.255.255.248 (255-248 =7-1 broadcast=6 ) hence you have 6 IP

68.3.2.1- 68.3.2.6 will be you IP's to be used for external WAN communication and routing

so the subnetting is restricting or expanding you IP range i.e. available host in you network

hope this clears the subnetting in simple plain explanations...