2 default gateways, one to 0.0.0.0... with DHCP

1

A problem that I have here with Windows 7 (RTM) and Windows Vista (SP2), on multiple machines, is that clients get a default gateway of the DHCP server (like they should) but on top of that, also a default gateway to 0.0.0.0.

This only happens when the computer starts up, not after I do a /release and /renew or when I run from an elevated command prompt: "route delete 0.0.0.0 mask 0.0.0.0 0.0.0.0".

DHCP is running on Windows Server 2008 R2 (RTM) (2 servers with split scopes), machines have different network adapters (one is a Marvel Yukon, the other a Realtek) and all drivers are up-to-date, including the drivers on the servers.

Any suggestions?

Jeroen Landheer

Posted 2009-09-24T20:16:09.580

Reputation: 380

Answers

1

Two suggestions:

  1. Check if IPv6 is disabled ("Disable and Turn Off IPv6 Support in Vista")
  2. Check any new firmware for the router or a new driver for the NIC

EDIT

Actually, it's quite normal to have a 0.0.0.0 route. Everybody has one, as this is the Default route:

A default route, also known as the gateway of last resort, is the network route used by a router when no other known route exists for a given IP packet's destination address. All the packets for destinations not known by the router's routing table are sent to the default route. This route generally leads to another router, which treats the packet the same way: If the route is known, the packet will get forwarded to the known route. If not, the packet is forwarded to the default-route of that router which generally leads to another router. And so on.

harrymc

Posted 2009-09-24T20:16:09.580

Reputation: 306 093

I tried to disable IPv6, but this didn't make any difference. NIC drivers are up-to-date, the router here is a simple network switch which doesn't do anything else except packet forwarding... – Jeroen Landheer – 2009-09-27T03:35:48.813

simple switches won't have (updatable) firmware, but if it's a router acting like a switch it might. – quack quixote – 2009-10-09T02:31:41.067

ockquote>

Actually, it's quite normal to have a 0.0.0.0 route

This is not correct - while the Default Route Destination of 0.0.0.0 is normal, there must be an associated physical gateway to handle the default route. A Default Route of 0.0.0.0 and Gateway of 0.0.0 makes no sense - thus all the problems with Vista and Gateway 0.0.0.0 – Mike – 2009-12-13T03:58:16.743