Windows 7 x64 :: Strange Routing Behavior?

Question

Say I have two NICs in my PC. One set for DHCP and one with a static IP.

The DHCP NIC gets IP/mask/gw/dns/etc in say 192.168.0.0/24 ... say it obtains an IP of 192.168.0.99/24 with a GW of 192.168.0.1.

The other NIC is set to a static IP without a gateway (used for administering devices locally via IP for instance, nothing else) ... give it just the IP/mask which lets say is 10.0.0.99/24.

Say I ping -t 10.0.0.1 and there's no device at that address (keep in mind both NICs are active/linked). Why will windows do this sort of thing when 10.0.0.0/24 is on the other NIC ... why would it even attempt to go to a different NIC/subnet like this?

request timed out.
request timed out.
Reply from 10.0.0.99: Destination host unreachable
Reply from 192.168.0.1 : Destination host unreachable
request timed out.

Reply from 192.168.0.1 : Destination host unreachable
request timed out.
request timed out.
Reply from 10.0.0.99: Destination host unreachable

This issue never existed in XP, I've never tried Windows Vista so not sure of it's behavior but I find it very odd.

Is there some a new protocol Microsoft invented? It doesn't really cause me problems, I just find it unexpected.

Answer 1

Your "default gateway" is the gateway to outside of your network. I would think you're seeing this because when Windows can't find an address on the local network(s), it will try to use the gateway to get out to other networks.

At that point you get a response from you router (192.168.0.1) telling you it has no known route to the requested network/host (Destination Host Unreachable).

This probably seems.is different from XP because Vista/2008 got a new network stack (the "Next Generation TCP/IP Stack"; IPv6, etc.).