Using Backup Routers With Windows XP and Windows 2003 Clients

If you give a Windows XP or Windows 2003 client multiple gateways, and
establish one with a metric of 1 and the other with a metric of 2, is
Windows capable of detecting the failure of the router with metric 1 and
automatically switching over to the other router?

I vaguely remember that doing this with real routers requires a routing
protocol in order for the router to figure out that one of its upstream
routers is no longer available. Protocols like RIP are a hassle, and I
certainly don't want that on the clients. I'm hoping Microsoft has its own
technology for detecting this situation and allowing the client to use the
alternate router.

I realize that one could delegate all of this to the router itself, but that
creates a single point of failure in the network, and I'm toying with
options to make things more robust for clients without introducing "high
availability" versions of routers and firewalls that are more expensive,
difficult to configure, and more difficult to keep running. If the clients
could automatically react to a router or firewall failure on their own and
switch to an alternate, things could be made very robust with minimum
hassle.

--
Will




Will

Hi Will,

This article should help you out,

Default Gateway Behavior for Windows TCP/IP
http://www.microsoft.com/technet/com...uy/cg0903.mspx

--
Mike
Microsoft MVP - Windows Security

"Will" <westes-(E-Mail Removed)> wrote in message
news:(E-Mail Removed) ...
> If you give a Windows XP or Windows 2003 client multiple gateways, and
> establish one with a metric of 1 and the other with a metric of 2, is
> Windows capable of detecting the failure of the router with metric 1 and
> automatically switching over to the other router?
>
> I vaguely remember that doing this with real routers requires a routing
> protocol in order for the router to figure out that one of its upstream
> routers is no longer available. Protocols like RIP are a hassle, and I
> certainly don't want that on the clients. I'm hoping Microsoft has its
> own
> technology for detecting this situation and allowing the client to use the
> alternate router.
>
> I realize that one could delegate all of this to the router itself, but
> that
> creates a single point of failure in the network, and I'm toying with
> options to make things more robust for clients without introducing "high
> availability" versions of routers and firewalls that are more expensive,
> difficult to configure, and more difficult to keep running. If the
> clients
> could automatically react to a router or firewall failure on their own and
> switch to an alternate, things could be made very robust with minimum
> hassle.
>
> --
> Will
>
>

"Miha Pihler [MVP]" <mihap-(E-Mail Removed)> wrote in message
news:eDt$(E-Mail Removed)...
> This article should help you out,
>
> Default Gateway Behavior for Windows TCP/IP
> http://www.microsoft.com/technet/com...uy/cg0903.mspx

So if I read this article correctly, we can use DHCP to configure two
default routes for every Windows computer on our internal network. One of
those will be a primary with metric 10 and the other is the backup with
metric 20. For just TCP-based activity, any Windows client will
automatically detect a failed router after three attempts to connect through
it and then switch over to the other router for that connection.

The key thing is to not have routers on multiple interfaces. But multiple
routers on a single interface, when the metric makes clear which is the
primary, should work reliably.

--
Will