I've been connecting to my router via a DHCP connection for a long time. We've had several instances where small changes from another computer to the router caused a network wide failure usually fixed by reseting the router or getting a new router.

Yesterday, my dad noticed an "intruder" as noted by Cisco Network Magic Pro on our WPA2-SPK (or w/e it's named) secured network and blocked the Mac address from connecting. Then things started going down hill. My laptop couldn't get online but it has a different MAC than what we blocked, then my iPod then my mom's iPad all couldn't connect but my mom's laptop could still connect - both she and I have MacBooks.

I noticed that the router was sending the wrong IP and sub-net mask to the devices. Usually something like 207.163.157.129 and a subnet of 255.255.0.0. And this is consistent through all of our router failures, both old and the current router.

So, would switching to a PPPoE, PPTP or L2TP be an alternative? How would the username and password be handeld?

Or should I try a Static IP? I'm at a loss. No other home network I know of has this much difficulty with their network it seems.

If this is an internal home network, your machines should have addresses either on 192.168.0.0/16 (usually 192.168.0.0/24 or 192.168.1.0/24 for home networks) or on 10.0.0.0/16 (enterprise networks). The reason some devices still work is that their DHCP leases have not yet expired. When they do, nothing will be able to connect. Can you detail your architecture, including ISP bridge (cable modem?), gateway modem, and any additional modems, along with machines and where they connect to?

Yeah, or router IP is 192.168.0.1 and the devices share similar. But whenever one of us can't connect, our assigned IP is random and no where in the same neighborhood of the routers.

My home network uses a D-Link 615 Router (with Hardware version C1 and firmware 3.12NA) which connects to a Comcast/Arris Modem (unsure of the model) via ethernet cable, and right now I have an ethernet cable from my laptop to the router.

A computer in the garage and a computer in the office connect to the router via ethernet 24/7. The three laptops, three phones and the tablet are all wireless through the router. We're running a Wireless G.

Can't think of anything else.

So the DLink router's WLAN port is connected to the ISP's device, and the remaining wired connections are to the non-WLAN ports? When you can't connect, Windows usually assigned you a 169.0.0.0/8 address, in my experience, which in ipconfig /all is tagged as a private address. Is this what you're seeing atm?

PPPoE/PPPoA/etc are related to connecting to your ISP (WAN), whereas your problem sounds like it's on the LAN side.

By "share similar" I assume you mean 192.168.0.x where x is greater than 1? What's your IP lease time? "Forever" seems common enough - can you check the DHCP client list to see what it's reporting? I know the Wii attempts to renew its IP about twice a minute when in standby mode.

Correct. Nope. Everything appears normal

Indeed The router seems to set the DHCP to expire after two weeks (Expires March 9th on the list) but in ipconfig on Windows it says my lease expires in 30 minutes after being obtained. I forgot about the consoles, both the Wii & the PS3 connect wirelessly. Wow, TWICE a minute?

I am not sure what it's doing, to be honest. It quite surprised me the first time I looked in the router log after the Wii was added to the network (even odder is that it doesn't do that when switched on, only in standby). My angle was to check the DHCP client list in case the router was (for whatever reason) running out of IP addresses, though this would seem very unlikely.

Speaking of which, does your router's log show anything of interest?

I also assume you don't have any machines on the network with a conflicting static IP address? If you enable Internet connection sharing in Windows it will set that adaptor's IP address to 192.168.0.1 and run a DHCP server, which would no doubt wreak havoc if that adaptor was then plugged into the same LAN that everyone else is trying to use. You could try changing the router's IP to something else (mine uses 192.168.2.1 and assigns IPs in the range 192.168.2.x, which I guess is the default for Belkin routers) which would avoid this issue in future.

o.o I just realized the router thinks it's March and it's really May. A wrong date could be rather bad, right? But other than that, I don't see anything odd.

That is correct

Quite extremely bad.

Seriousness. Followed by a joyful smile. Means seriousness is dead serious

Exactly. So bottom line, can you try syncing the date on the router and seeing what that does to your network fabric's consistency?

We've managed to fix it. I'll check the router log as soon as I can.

Excellent, I'll be interested to know what the point of failure was for future reference.

I doubt we'll ever know. All we do when this happens is reset the router and set it up from scratch again. We don't really do any debugging. Next time it happens though. I'll save the logs and everything I can to document.