Odd IP address issue

[hcrider]

I have a network that consists of serveral off site locations. One location is using an IP address that is outside the assigned range for that location as a gateway and as a DNS server. The problem is that that IP address doesn't exist. There is no server, workstation, swtich, router, etc with that IP address. It doesn't ping and can't telnet to it. Yet when I change the settings, nothing at that location can connect to the network.

Is there a way to resolve this?

 

[elgrandeperro]

You must be using it for something. Only test from WITHIN that network, and see if you can ping it. Check your router to see if it uses it. What exactly fails? Web browsing, DNS, or everything.

My guess that someone "borrowed" a registered IP range (look it up using whois) and is using it for something internally.
I would guess your router would have to know something about it.

 

[hcrider]

I've tested inside from a local machine. Pings come back timed out. I can check the router, but there isn't even a DNS record of it existing. It's an internal IP address.

Everything that utilizes the network fails. Loses IP address, can't connect to network resources, the whole nine.

 

[elgrandeperro]

If it is on the net does it have an ARP entry? If it does, then it is a real device.

 

[lhuegele]

So what you're saying is that every device on the remote network is pointing to a gateway address that you don't know where the devices is? When a ping times out, that only tells you that device is not responding to pings. It doesn't mean that device doesn't exist.

How do you know the IP address is internal? Perhaps the IP belongs to the ISP that services that remote site??? Perhaps some routing is taking place via the ISP's router for that site or something....

Good luck

 

[SimonDavies]

Silly question but have you checked all machines to ensure that none of them is dual homed (ie has two network cards in the box)?

What happens if you do a route print? or a tracert? or even a pathping from the internal network to one of the remote sites (as I am assuming that they do connect still)?

SimonD.

The real world is not about exam scores, it's about ability.

 

[stfaprc]

also, see what traceroute does going and coming

 

[hcrider]

Sorry for just checking back in.

It is an internal IP address due to the 192.168 part of it, unless I'm wrong. I did a tracert on it and it went to an outside source. Turns out that it was an old modem that was outside the network that was used for something else. The cabling in the building was not done very well and the port forwarding was way outta whack. I think I just about have a grip on it.

Thanks guys.

 

[lhuegele]

Glad to know you traced it down. Good luck.