Some of the Microsoft guys tell me that this has been
improved in OSP2 (The OEM service pack that most
of us can't get.)
In the regular version of Win95, it's seems quite broken...
Allow me to give an example:
You have a NIC card in your PC with a fixed IP address
(or a DHCP lease active, take your pick.) You dial up
to a different network number. You can still talk to your local
subnet via the Ethernet card, but everything else goes
out the modem (default route.)
If you happen to dial into the SAME network (like in my case,
I have a fixed IP on my NIC for my Class B, and I dial
into the same Class B.) You will go out the modem
for everything, even your local subnet.
It's kinda strange if you look at the route tables..(netstat -rn)
with the two situations... the way it "turns off" your NIC is
to change all of it's routes to a metric of 2, and puts in replacement
routes (going out the modem) with a metric of 1.
In the case where you can still use your NIC card, it had gone ahead
and chnaged the route metric for that route to 2, but not added a
matching route at metric 1.
The reason I know all of this is because it cases some problems..
If one of my users with a laptop goes home, and tries to dial
in (with his PCMCIA ethernet card with the static IP still in the
machine) he can't reach anything on his "home" subnet at the office,
because the packets are spilling out the side of his laptop instead
of going out the modem. Windows 95 can't tell
(usually) if the NIC card has link or not.
Now...there is a setting in the registry for IP Forwarding (you can
see it's state when you look at winipcfg) that I have not
played with...I'd be curious to hear from folks who have. Regardless,
I don't think there is anything that will let Win95 listen to any route
protocols (not even RIP) and I have had zero luck getting
it to pay attention to any of my route add/delete/change commands.
---------- Previous Message ----------
To: firewalls, firewall-1
From: martinw @ epcorp.com ("Martin C. Walker") @ smtp
Date: 12/12/96 08:53:39 AM
Subject: IP forwarding/routing in Win 95
I have heard here the dangers of Win 95 boxes with modems living
behind firewall because Win 95 has IP forwarding or routing capabilities.
I'd like to take advantage of this to use my Win95 dial-up-networking
and a "real" network card to make my '95 box a crude dial router for
some quick and dirty firewall building/testing I'm doing.
Can anyone enlighten me as to how this works/how to set it up ?