I had the basic home security installed this week. I had no existing hard-wired security system. The installer attached a second router to the cable modem and went about his install and all internet traffic crawled to a 30 cps dail-up mode. The installer's opinion was "this should not happer/affect your current internet speed"; it obviously did. I had him attach the new Home router to the existing router, shut everything down, rebooted, used the iPad to complete the installation, and somehow, eventually, internet speed seemed to come back up to what it was.
My current router was max'd out, re: ethernet wire connections. I would have expected the install to handle that via an unmanaged switch instead of a second modem.
Questions:
1) Why a second router vs a switch?
2) If a second router is required, doesn't that require modifying settings in the routers? The second router, given what I know, creates a subnet, and the degradation of internet speed seems to have been caused by the routers competing against each other.