I have a Linksys RV042 dual wan router that is great. I'm using it with a primary and a backup connection for an office. The problem that I'm having is that sometimes when the primary goes down the rollover doesn't happen and I have to unplug the primary. It identifies the loss of connection instantly if you unplug it but recently our provider reassigned our IP to another client and it did not rollover! I have used the settings of the RV042 to ping for DNS server and the user definable IP but these settings do not help. Otherwise a great device.