There are many versions of that router so check if the firmware is current.
Again, the n600 has more than one version so I can't tell you to see if firmware x.yz is in it. You have to look at the version of the router then compare that to what's up at the maker's site.
Wife works from home via Citrix VPN and Ethernet into the router. When she connects, we loose the internet and network in the whole house except for her connection (I've even tried Ethernet into the laptop, but no go). Motorola Surfboard SB 6141 modem and Netgear N600 wireless router. I'm hearing that maybe a new (larger,faster) modem is in order. HELP!! Any thoughts, y'all??