We have a BEFSR81 v3 and when we try to connect a PC to any port it shows disconnected on PC and no Lan light. We called support and they had us plug cable from modem to router into port1 and the light does come on. We have checked the cables and can bypass the router and connect to internet no problem. I am trying to troubleshoot a remote office so I am not able to see the setup but directing a user to help troubleshoot. Thanks! Eric PS. Since post, Linksys support has helped us chang the IP address of the router to 192.168.2.1 from 192.168.1.1 and that seems to have resolved the problem. I am not sure how that was accomplished since we could not access the router via the browser but I am happy it is working again.