Very odd sudden change

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Gingermagic
Posts: 5
Joined: Fri Feb 19, 2021 12:53 pm

Very odd sudden change

Post by Gingermagic » Fri Feb 19, 2021 1:10 pm

Hi All,

I've have had a Billion 7800 router for years. It's been great, and worked very well.

I add static IP addresses in Advanced > Configuration > LAN > DHCP Server > Fixed Host
And I use the 192.168.0.x range.

On the devices themselves, I've tended to leave them set to auto/DHCP, and the router assigns the correct IP based on the MAC address that I've assigned.

I have the DHCP server set from 192.168.0.120 to 192.168.0.200. That takes care of mobile phones and anything that I'm not bothered about having a static IP address for.

A couple of nights ago, I added a new static IP address, for a mini PC (Odroid N2+, attached to projector). I thought that this already had a static IP, but noticed that it hadn't, so I set one.

As far as I can remember, I'm sure that I didn't change anything else on the router!

I noticed that I also had to set the IP settings on the mini PC. No problem, but I don't usually have to do that.

Since then, the whole network has been falling down!

The linux server went first, which I fixed by adding it's own static IP address into the settings (turning auto/DHCP off).

Then the Windows 10 boxes started dropping like flies.

After searching online, I've been using this to fix them ...

Code: Select all

netsh interface ip set address name="Ethernet" static 192.168.0.x 255.255.255.0 192.168.0.xxx
netsh interface ip set dns name="Ethernet" static 192.168.0.xxx
I've got other things plugged into the network, which have static IP's in the router, which have always worked, but now don't. Some of them, I'm not sure how to set internal IP's for.

Then there's mobile phones. They just aren't working at all.

They seem to be trying to connect with 169.254.xxx.xxx addresses. Why on earth are they doing that?

The DHCP settings, in the router, seem fine. I've even compared them with screenshots, of the same screen, taken a few years ago (with the network in it's previously working state).

Any idea what could be going on?

Thanks,
Damian

Gingermagic
Posts: 5
Joined: Fri Feb 19, 2021 12:53 pm

Re: Very odd sudden change

Post by Gingermagic » Fri Feb 19, 2021 1:11 pm

PS
My 7800 router doesn't have WiFi. That comes from an access point that I've got plugged into it via a lan cable.
That too has been working fine for years.

billion_fan
Posts: 5266
Joined: Tue Jul 19, 2011 4:30 pm

Re: Very odd sudden change

Post by billion_fan » Fri Feb 19, 2021 1:29 pm

Gingermagic wrote:
Fri Feb 19, 2021 1:11 pm
PS
My 7800 router doesn't have WiFi. That comes from an access point that I've got plugged into it via a lan cable.
That too has been working fine for years.
It sounds like the DHCP server has failed hence you getting 169 address from the router, try disabling the DHCP server and re-enabling it.

Gingermagic
Posts: 5
Joined: Fri Feb 19, 2021 12:53 pm

Re: Very odd sudden change

Post by Gingermagic » Fri Feb 19, 2021 1:42 pm

billion_fan wrote:
Fri Feb 19, 2021 1:29 pm
It sounds like the DHCP server has failed hence you getting 169 address from the router, try disabling the DHCP server and re-enabling it.
Thanks for the super quick reply billion_fan,

I just disabled DHCP and clicked apply.
Then re-enabled it, checked that all settings were still OK (they were) and clicked apply.
Unfortunately, it doesn't seem to have fixed anything. Phones are still trying to connect to 169.xxxx and I've rebooted devices which used to go to static IP's, and they still aren't.

Any other ideas. It's really got me scratching my head ... and the family tutting at me! :-)

billion_fan
Posts: 5266
Joined: Tue Jul 19, 2011 4:30 pm

Re: Very odd sudden change

Post by billion_fan » Fri Feb 19, 2021 2:08 pm

Gingermagic wrote:
Fri Feb 19, 2021 1:42 pm
billion_fan wrote:
Fri Feb 19, 2021 1:29 pm
It sounds like the DHCP server has failed hence you getting 169 address from the router, try disabling the DHCP server and re-enabling it.
Thanks for the super quick reply billion_fan,

I just disabled DHCP and clicked apply.
Then re-enabled it, checked that all settings were still OK (they were) and clicked apply.
Unfortunately, it doesn't seem to have fixed anything. Phones are still trying to connect to 169.xxxx and I've rebooted devices which used to go to static IP's, and they still aren't.

Any other ideas. It's really got me scratching my head ... and the family tutting at me! :-)
Have you tried to remove the device you added to the fixed host option (mini PC (Odroid N2+, attached to projector) removing the rule you added??

Also try a isolation test, unplug everything from the router, leave 1 PC connected to the router, and reboot the router, then see if the one PC has obtained a IP address from the routers DHCP.

Gingermagic
Posts: 5
Joined: Fri Feb 19, 2021 12:53 pm

Re: Very odd sudden change

Post by Gingermagic » Sat Feb 20, 2021 12:24 am

billion_fan wrote:
Fri Feb 19, 2021 2:08 pm
Have you tried to remove the device you added to the fixed host option (mini PC (Odroid N2+, attached to projector) removing the rule you added??
What a plonker I've been!

It hadn't even crossed my mind that I'd made a mistake with the new entry. If I had, I'd have expected the single device not to work, not the hold network to collapse.

Removing the Odroid line from the Fixed Hosts list has fixed everything! :-)

Thanks so much billion_fan!!

What would you recommend with all of the Windows and Linux computers that I've changed? Should I keep them with their current static IP addresses, or switch the actual devices back to Auto/DHCP, and let the router assign the IP addresses (like I've always done it in the past)?

Thanks again,
Damian

billion_fan
Posts: 5266
Joined: Tue Jul 19, 2011 4:30 pm

Re: Very odd sudden change

Post by billion_fan » Mon Feb 22, 2021 9:24 am

Gingermagic wrote:
Sat Feb 20, 2021 12:24 am
billion_fan wrote:
Fri Feb 19, 2021 2:08 pm
Have you tried to remove the device you added to the fixed host option (mini PC (Odroid N2+, attached to projector) removing the rule you added??
What a plonker I've been!

It hadn't even crossed my mind that I'd made a mistake with the new entry. If I had, I'd have expected the single device not to work, not the hold network to collapse.

Removing the Odroid line from the Fixed Hosts list has fixed everything! :-)

Thanks so much billion_fan!!

What would you recommend with all of the Windows and Linux computers that I've changed? Should I keep them with their current static IP addresses, or switch the actual devices back to Auto/DHCP, and let the router assign the IP addresses (like I've always done it in the past)?

Thanks again,
Damian
That's upto you, I don't see any issues with the current configuration as static IP's on the device it self should override anything set by the router.

Gingermagic
Posts: 5
Joined: Fri Feb 19, 2021 12:53 pm

Re: Very odd sudden change

Post by Gingermagic » Mon Feb 22, 2021 9:39 am

Thanks again billion_fan,

I decided to just switch the ones that may, some day, connect to other networks back to Auto.

Thanks again,
Damian

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