Connecting Personal and Private Routers to Modem


Mar 9, 2012
Currently, at my business I have:
Cable Modem (Charter Internet)
Cisco Router (Supplied and managed by outside company)
Computers and printers (all hardwired)

The network consists of 3 company computers and 2 company printers. There are also 2 "personal" computers on the network. Those personal computers tend to be very slow when connecting to the internet. Plugging a computer directly into the modem fixes the speed problem.

The router is managed by a third party. I need to request changes to the router, which often requires pulling teeth. I asked a few years back to open a port on the router for remote viewing of the security cameras, and after hours of "TELLING" them to do it, it took them 30 minutes over a dial-up modem to open the port. The reason I was told was because the Cisco router is old and doesn't have a GUI, so it's all coding.

What I want to do is add "something" between the modem and the Cisco router. The only issue is I don't know what ports would need to be open for the network to work properly. Another idea was a switch after the modem, to them split to the company Cisco and to a "personal" router. However, I'm pretty sure Charter won't allow multiple IP addresses after the modem.

Any suggestions or help would be greatly appreciated.


Jan 25, 2012
In your current setup the Cisco is probably acting as a DHCP server, so adding another one before the Cisco will not do. You can probably add a switch between the modem and Cisco router but any device you connect to the switch will need to have its TCP/IP addresses (IP, Subnet, Gatway and DNSs) manually added.