Hi all, Hope this isn't a redundant post but I Googled the whole website for "ARP cache" and couldn't find anything similar so... if you have any advice on what could be causing the following problems w/my wireless router, please let me know! It's a pretty basic residential setup... just one wireless router that my 2 roommates and I connect to on our laptops (1 Mac & 2 PCs). For the last couple days the router (WRT54G) hasn't been working--my roommates & I can each see the wireless network & connect to it on our laptops, but once you're on the network you can't actually connect to the internet. But if I plug the modem directly into my laptop w/an Ethernet cable, I can get on the internet. So it's basically a problem with the wireless router connecting to the internet. My roommate thinks it may be related to the power going on & off several times Sunday night during a blizzard just because it happened at the same time, but we're not sure. Monday I installed Norton Antivirus on my Macbook for the first time (coincidental timing, I wanted to do a virus scan because it had been acting funky... but it was unrelated hard drive issues. ...it's been a good week.) And just today I noticed that whenever I am connected to the wireless router I am bombarded w/"ARP Cache Poison" alerts in Norton... by "bombarded," I mean like faster than one per second. When I connect straight to the modem & skip the router, I don't get the alerts. I am not a hardcore techie so I did a little research into WTF an ARP Cache Poison is, but am still confused about if this could be causing/related to our router problems (sure seems like it but I guess it is hard to know for sure since I installed Norton after the router problems started), and how to fix it. Would it help to know what MAC address the "ARP Cache Poisons" are coming from, and/or the IP & MAC addresses that I see in my ARP cache, or is that not stuff I am supposed to be putting out on the internet for all to see? (haha, I know I sound like such a clueless old person... ) I will say that when I am connected to the wireless router, my ARP cache shows no MAC address associated with my router IP, it just says (incomplete). It also shows "ff:ff:ff:ff:ff:ff" as the MAC address associated w/another IP that is similar to my router IP but not the same. Those are the only 2 things in the ARP cache. Also, even when I am connected to the wireless network but the router is unplugged from the modem, the "cache poison" notifications continue to pile up. Oh and final additional fact, when I am connected to the wireless network & type in my router IP to try to look at the router settings in my browser, I can't... nothing happens/the page doesn't show. Any thoughts?? Or anything else that would be helpful to know? I am pretty clueless here. Thanks in advance!