Can you connect both switch and modem on a router?

[FPerson]

First time here, sorry if this question is 'nooby/retarded'.
Anyways, lets say a bank is using a star network topology for their network structure. The center component is the network switch whilst multiple routers are connected to it. Also, these routers have workstations/server connected to them.
Could I have a modem connected to one of those routers (which the router is also connected to the network switch) which will allow remote devices (phones, laptops etc) have access to the internet? Considering that the router provides wireless connection.
Note: the modem is not connected to the switch.

 

[PP Mguire]

The first question that comes to mind is, why is a level 2 device the center of level 3 devices? What's the purpose of this? The second question that comes to mind is, why would a bank have such an odd and backward network set? The third question being, why would you need to hook a modem up to this setup to provide wireless access to what I'm assuming is guest devices?

 

[FPerson]

I've heard that in a star topology network, a switch or concentrator is used as a centralized 'manager' for data transmission. I'm guessing that whenever a data packet is sent to the network switch by the router from a workstation (computer), the switch will send it to the intended destination/port. But, I'm skeptical of this (my) interpretation.
I chose a bank as an example, but I really meant any type of business.
I'm assuming that a router provides users accessibility to the business's local area network, but does not necessarily mean that they will be connected to the Internet. That's why I added a modem so it can connect to the ISP which will provide users cable/DSL internet service. Then again, I may be all wrong about this.

 

[PP Mguire]

Utilizing star in a big business you won't have any routers and very little if any level 3 devices (which a router is). Your gateway/DHCP/etc management will be done via a server and your centralized "point" will be a cluster of uplinked switches usually connected via SFP+ or fiber for high bandwidth.

Most all homes use star as the router (your level 3 device) is your central hub and everything connects to it.

In the sense that you're talking, you'd have one switch in the middle with routers connected to them and then the workstations behind that. In common definition a router will be like your typical home router which is a level 3 device that provides DHCP, firewall, NAT, and typically wireless as well. In which case that wouldn't make any sense to set it up the way you mentioned, then have a node off to the side that has its own modem that provides internet access. A setup like this would usually have your network setup like I mentioned before, with your modem/gateway off to the side into a hardware firewall that connects to the central network. Then if you wanted wireless for guests an AP would be VLAN'd for that specific situation behind the firewall but separate from the main network. These usually carry their own subnet and DHCP/DNS/WINS server.

 

[FPerson]

I see what you mean, thank you for the clarification

 

[Johnywalter]

For those of you who have or are familiar with fibre home networks, you will know that the fibre cable goes to an ONT (Optical Network Terminal) which connects to a router that connects all your devices at home.

My question is instead of using a router, since I will only be connecting my devices (desktop, xbox, and tv) via ethernet cable, can i use a gigabit switch instead of a traditional router. Ive read that switches are great for minimizing packet loss and latency in terms of gaming, but can they also act like a router?

 

[PP Mguire]

For those of you who have or are familiar with fibre home networks, you will know that the fibre cable goes to an ONT (Optical Network Terminal) which connects to a router that connects all your devices at home.

My question is instead of using a router, since I will only be connecting my devices (desktop, xbox, and tv) via ethernet cable, can i use a gigabit switch instead of a traditional router. Ive read that switches are great for minimizing packet loss and latency in terms of gaming, but can they also act like a router?

Your ONT doesn't provide DHCP for your network, translate NAT, and usually requires authentication of some sort from the gateway provided by your ISP. That last one is only true 50% of the time but for the rest you still need some form of gateway between a level 2 switch and your devices.