I have the following network topology:

  • Remote admin network ( I connect to using PPTP to the public IP
  • Remote gateway assigns an IP adress to me (, for instance)
  • I can reach any server on the subnet
  • I cannot reach any server on the (DMZ) subnet
  • Note that I added a static route in Windows in order to route the traffic to through the VPN's gateway (

Persistent Routes:
Network Address Netmask Gateway Address Metric 1

(sorry for poor formating)

However when I do a trace route, I can clearly see that Windows is routing the packets to my default, non VPN, gateway:

Tracing route to over a maximum of 30 hops

1 1 ms 1 ms 1 ms my.firewall []
2 5 ms 4 ms 4 ms
3 (edited out public ip) reports: Destination net unreachable.

How can this be? Why is Windows routing to my default gateway ( when I explicitely specified a different gateway for this destination subnet ( ?

  • could you provide the complete output of route print, ipconfig /all and which windows version you are using? – john May 14 '11 at 14:34

Sorry for answering my own question but here goes.

Basically I simply had to re-add the route manually (route add MASK Doing this fixed the issue. Apparently, even though the route shows as "Persistent" it was not. This happens whenever I reboot. I don't know if it's a bug or simply because interface numbers can change between two reboots (both sound very doubtful but that's all I can think of).


Without further info I would guess you need to provide the interface number when adding the route. For example if the vpn if is number 18 then

route -p add mask if 18


Edit: Serves me right for writing this on my phone w/o access to a computer.

The route you're manually adding should reference the IP assigned to the local machine's PPTP interface, not the default gateway on the remote network. It's counter-intuitive, but it'll work. For a long-term solution you can use a DHCP option to push out the route.

  • Sorry, I should have mentioned that the remote server's PPTP interface is the default gateway on the remote network. – Astaar May 17 '11 at 14:26
  • @Furism: I dropped on an edit because my recollection was poor. – Evan Anderson May 17 '11 at 14:32

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