Destination net unreachable.

Energize · 10 Feb 2014 at 13:21

Inexplicably a windows xp machine stopped connecting to the internet this afternoon, lan connection says connected, however trying to ping the router gives me "destination net unreachable", I've tried both ethernet cards in the computer and it doesn't make a difference. All the other computers on the network work fine, both wireless and ethernet, I've even tried using a different port on the router.

bremen1874 · 10 Feb 2014 at 14:22

What does IPCONFIG /ALL at a command prompt tell you?

Energize · 10 Feb 2014 at 14:37

Anything specific I'm looking for? I'm on a phone now because after resetting the router to factory settings now nothing will connect.

All the ip addresses displayed are 10.10.10.x which is obviously wrong.

If I type 10.10.10.254 I'm asked for a username and password for server WR5201 which Google says is a completely different router!

GefGz · 10 Feb 2014 at 18:42

Energize said:
Anything specific I'm looking for? I'm on a phone now because after resetting the router to factory settings now nothing will connect.

All the ip addresses displayed are 10.10.10.x which is obviously wrong.

If I type 10.10.10.254 I'm asked for a username and password for server WR5201 which Google says is a completely different router!

10.10.10.X is a private subnet much like 192.168.1.x - It doesn't mean it's wrong, just that it's getting the range from DHCP

I'd just go into Tcp/IP settings and set an assigned IP that's in the range of your router (Most probably 192.168.1.X on home equipment but apparently you're setup for 10.10.10.X) and set the DNS to 8.8.8.8

Also can you go to run>cmd and type "arp -a" and copy/screenshot the outcome

Energize · 10 Feb 2014 at 20:57

I managed to solve the problem by disconnecting everything from the router and using ipconfig /release and then ipconfig /renew, that reset the ip to the correct address of 192.168.1.x and I was able to access the router again. Seems for some reason all the computers had started using the wrong gateway. Need to find out why now.

GefGz · 10 Feb 2014 at 20:58

Energize said:
I managed to solve the problem by disconnecting everything from the router and using ipconfig /release and then ipconfig /renew, that reset the ip to the correct address of 192.168.1.x and I was able to access the router again.

Boo I was looking for some troubleshooting fun :mad:

Damn you

Energize · 10 Feb 2014 at 21:20

Trust me it was anything but fun lol.

Can I prevent this kind of thing happening again by configuring the pc's to use 192.168.1.254 as the gateway rather than using dhcp?

GefGz · 10 Feb 2014 at 21:50

Energize said:
Trust me it was anything but fun lol.

Can I prevent this kind of thing happening again by configuring the pc's to use 192.168.1.254 as the gateway rather than using dhcp?

If you set the IP/Subnet and gateway it will be fine.

What's strange is the fact that your router is dishing out a different range in the DHCP settings, might want to check that.

It should be issuing 192.168.1.x as standard if it's gateway is set as .254 - The settings have been changed for some reason

Energize · 10 Feb 2014 at 22:20

The computers had started using another router on the network as the gateway, this was assigning ip addresses in the 10.10.10.x range.

bremen1874 · 10 Feb 2014 at 22:37

You had/have two routers on the same network, both with DHCP enabled?

GefGz · 10 Feb 2014 at 22:39

bremen1874 said:
You had/have two routers on the same network, both with DHCP enabled?

Yeah Energize, once you change routers all you would have needed to do would be release renew ipconfig, as you did.

From now on it should just be fine

Energize · 10 Feb 2014 at 22:49

bremen1874 said:
You had/have two routers on the same network, both with DHCP enabled?

To my knowledge the second router did not have dhcp enabled, it had been installed prior to my involvement with the business and was being used as a wireless ap. I still don't understand why there was no issue until today.

bremen1874 · 10 Feb 2014 at 22:58

Any chance that someone unauthorised may have decided to try some DIY trouble shooting?

If you're using a router as an access point all it'd take is someone hitting the reset button. I'd at least tape over the reset button to hopefully dissuade people, and possibly leave evidence of any tampering.

Energize · 10 Feb 2014 at 23:10

Well that's certainly possible come to think of it. Believe it or not there is an ethernet cable running from the router in the office to the ap in a caravan that one of the employees lives in on the site.

Is there any way to protect the desktops from rogue dhcp servers, other than by manually setting the gateway and ip address for each computer?