A lot of strange things going on. Are you using the power adapter that came with the router? Is the firmware up to date? I would also try different Ethernet cables. Any issues if you power cycle just the modem or just the router? If your modem has logs, any events at the time of the failure?

 

Right after I posted the first message I updated the firmware. Just guessing there was no FW update available when I got the router & never followed up on it.

 

It's been 6 hours without a problem & hopefully everything will be OK now.

 

FWIW the power adapter that came with the router.is being used, & there are no issues when power cycling just the modem or router. Not sure if I ever tried different Ethernet cables long time ago but never tried different ones over the last couple days. I can access all kinds of stuff on the modem but never had a reason to see if it kept logs of events.

 

I'll post back in a few days with hopefully good news that everything is still OK.

 

The router worked for about 1.5 days.

 

It’s now doing what it did several month ago - changing the IP address back to the default 192.168.0.1 all by itself.

 

I’m not able to change it to 192.168.1.1 that is needed, or at least used to work. This was also a problem months ago.

 

When I try to change the IP to 192.168.1.1 an error message appears:
Error code: 5008
WAN IP address and LAN IP address cannot be in same subnet. Please input IP address.

 

My WAN Subnet Mask is 255.255.0.0 and the LAN Subnet Mask is 255.255.255.0. They are not the same.

I looked at the settings on my old D-Link router & the LAN Subnet Mask is 255.255.255.0.

 

I Googled Error 5008 and also WAN IP address & LAN IP address cannot be in same subnet. Most answers were about connecting 2 routers. A few mentioned restoring the settings, which is what I did when updating the firmware. Some discussed address & ranges & talked way over my head about this.

 

If some setting is wrong then why does the router work for a day?

What forces it to automatically change its IP address to the default?

 

Any ideas or suggestions?
Thanks

More information -

 

The DSL Modem is doing PPP on the modem. Router WAN connection type is Dynamic IP.

 

I changed the Router WAN connection type to PPPoE.
This changed the WAN Subnet Mask is 255.255.255.0. I Saved but did not reboot.
Was now able to change the LAN IP to 192.168.1.1. The LAN Subnet Mask is still 255.255.255.0.
Rebooted

 

Router WAN connection type changed back to Dynamic IP. Perhaps it never saved when I went to the LAN setup screen because I didn’t reboot while on the WAN screen.

 

Both WAN & LAN Subnet Mask are 255.255.255.0. FWIW the old D-Link router also has both at 255.255.255.0.
Interesting that Error 5008 says they should not be the same.
Everything is working at the moment.

 

Questions, questions -

Could DSL modems need both WAN & LAN Subnet Masks set to 255.255.255.0?

Why was my WAN Subnet Mask previously at 255.255.0.0?
Was it that way after I updated the firmware?
Or did whatever change the LAN IP address also change the WAN Subnet Mask to 255.255.0.0?

 

I’ll see how long this keeps working.

 

I lost the Internet connection again & the little yellow warning triangle is displayed on top of the Internet icon in the lower taskbar.

 

I can access the router & all the settings appear to be OK. But I cannot access the modem. I powered the router off & on a couple times but it made no difference.

 

Connected the PC directly to the modem & this gave me an Internet connection. I could now access the modem & downloaded the logs but have no idea what to look for.

 

Reconnected the router & have an Internet connection. I didn't change anything other than temporarily taking the router out of the circuit while keeping it powered up.

 

What the heck is going on?

 

You may have had an outage from your ISP. Some ISPs know if you power off or disconnect the modem for a period of time (ie 5 min) and does some type of reset of the modem. It may also reload new firmware. If you call your ISP, they may have you disconnect/power off the modem for 5 minutes as part of their diagnostic process. When you lost the internet, did any of the modem lights also change? The thing to look for is 'critical' messages at the time of the failure. If you get the same type of messages with each failure but not at other times, then those are the ones to follow up on. Cables do a lot of strange things and also consider the RG6 cables coming in from your ISP to the modem as spiltters and connectors can cause issues as can other devices on it such as TVs.

I don’t think the ISP reset the modem because it worked when I connected it directly to the PC, and when the router was reconnected to it. All I did was pull the router’s Ethernet cable from the back of the modem & plugged in the cable going to the PC and had an Internet connection. Then put the 2 cables back the way they were & also had an Internet connection. At this point everything is still working.

That’s pretty crappy if a home network system gets reset & stops working when you’re away from home. Some people monitor their house while on vacation.

There are no “critical” messages in the log & nothing that jumps out at me. But I never looked at the modem log before & am not familiar with it.

I have a DSL modem with a dedicated line going to it. I did change the Ethernet cables yesterday & will do it again when/if the system goes down again.

Presuming it happens again I’ll run the Windows Network troubleshooter before I do anything else.

 

Maybe this is a clue or means something -

When I lose the Internet connection the symptoms are similar to when I change the router’s NAT settings.

My DSL modem is frequently called a router because it does NAT. And I understand you’re not supposed to be doing NAT in both the modem & in the router. But if I disable the router’s NAT then I lose the Internet & cannot access the modem. Same as what’s happening now.

Any correlation there?

I was looking at some websites tonight & some were not responding. I'd get either a timed out or cannot find that site message. These sites were working earlier. Over the course of maybe 15-20 minutes I was having more non-resonsive sites. Eventually I could not access any sites or the modem. Modem lights were all normal. There was no yellow warning triangle on the network icon but I did a Windows > Network > Troubleshooting and it said "The DNS server isn't responding......Detected".

 

Connected the modem to the PC & had Internet. Put the router back in the circuit & had Internet. Never powered off or rebooted anything.

 

Next time I'll just remove the ethernet cable from the modem & wait a minute & plug it back it and see what happens.

 

Lost the Internet connection again.

 

Disconnected & reconnected PC from router, but no difference
Did the Windows > Troubleshooting & "The DNS server isn't responding......Detected".

 

Disconnected & reconnected modem from router, but no difference
Did the Windows > Troubleshooting & "The DNS server isn't responding......Detected".

 

Disconnected & reconnected both PC & modem from router, but no difference
Did the Windows > Troubleshooting & "The DNS server isn't responding......Detected"

.

Powered cycled the router, but no difference
Did the Windows > Troubleshooting & "The DNS server isn't responding......Detected".

 

I could not access the modem in any of the above scenarios.

 

Connected PC directly to modem & it works.

Reconnected the router & it works. And can access the modem.

 

I did not power cycle the modem.

 

Temporarily connecting the PC to the modem clears the problem.

 

FWIW, I did "flushdns" a day ago.

Any idea if the "DNS server isn't responding" problem in the PC or the modem?

 

 

Well I had a connection for a few minutes because I was able to post the above message.

 

Then I could not access any website, but could still access the modem & it's settings appeared OK, and it's lights were normal. After a minute or two the yellow warning triangle came up on the Network icon.

 

I powered the modem off & on. To my surprise I had to login, which I don't recall ever doing when powering off & on. Not sure why it's happening now. It did give me a new IP connection which might be good. We'll see.