Originally Posted by fcwilt
Yes you can cascade routers but why?
If you connect the WAN port of the second router to a LAN port of the first, the second network inherits the security settings of the first and that may not be desirable. Plus you take a performance hit.
With a router that supports multiple zones each zone is independent of the other, the security settings can be set exactly as needed without any worry about impacting the other network.
And the LAN1 to LAN2 security settings can be set as needed independent of the LANx to WAN security settings.
In all my years I have never encountered a case where cascading routers was the best approach.
Didn't say it was the best approach, but one of many options. To your other point, the second router more like extends (or layers on top of the first to be pedantic) the first one's security settings not just inherit it, which is ideal. To get around that, designating the second router as a DMZ within the first router will allow it to bypass the first router's firewall so that the second router has total control of its own security.
In addition, depending on use, network performance can be improved actually because there are essentially 2 subnets. E.g. if his mom's computer is doing a regular backup to a NAS (both within the second subnet), his video streaming from his media server to his Xbox or whatever (within the first subnet) does not get affected.
As I said earlier, the first router can be as open as he needed it to be for his use, then have the second one as secure as possible for his mom's use. I doubt his current router has the ability of multiple zones with their own dedicated security settings (most ISP's doesn't provide such router and he, the OP, probably didn't buy one as he didn't need/know of such feature). Furthermore, buying one with those capabilities is more expensive than getting a typical router as a secondary one. Anyway, that's just a suggestion.
Edited by ronnbot - 1/5/14 at 7:23pm