Re: NT and Cornell V1.0 TCP problem

ike relucio (ike_relucio@cyberdude.com)
Sat, 9 May 1998 11:46:06 +0800


i would guess that you are not one of the alpha testers of this new version.
have you also used cu-seeme before ? what version ? did you encounter this
same problem ?

the problem is the fact that once you dial-in to your ISP, your machine
effectively now has two IP addresses --- the one for your LAN and the one
assigned to you by your ISP. this confuses cu and probably a lot of other
software

i don't believe there is anything like an "IP binding order" --- your lan
adapter card needs an ip and your dial-up networking adapter needs an ip ---
it's as simple as that. an adapter card can only have one ip address
associated with it so there isn't any 'binding order'

i don't have a lan card with a second ip address installed in my system but
i think the problem is in the way the ip routing table gets messed up after
you dial-in to your isp. try comparing the output of the 'route print'
command before and after you dial-in to your isp. you will probably need to
run some batch file after dialing-in to correct the routing table. you will
probably need to set it in such a way that ip addresses that belong to your
lan network (10.x.x.x) gets routed to your lan network card and everything
else gets routed to the ip address assigned by your isp. unfortunately,
windows help entry for the 'route' command doesn't give you much info on how
to use the utility.

you might also need to turn on 'enable ip forwarding' in the tcp/ip
settings.

what happens if tcp/ip uses your lan ip address when it sends a packet out
to the internet ? well, since the lan ip address is not defined in any DNS
or router on the internet, there doesn't seem to be a way for the return
packets to find their way back.

you might be better of asking yourself the question: "do i really, really
need to be connected to tha lan at the same time that i want to connect to
the internet ?"

if your answer is no then make two hardware configurations and in one
configuration, enable the lan adapter and in the other one, disable it. so
when you want to connect to the internet, reboot and select the
configuration with the lan adapter card disabled, this way your lan ip
address will not be defined.

-----Original Message-----
From: Ian <virus@mad.scientist.com>
To: CU-SEEME-L@cornell.edu <CU-SEEME-L@cornell.edu>
Date: Saturday, May 09, 1998 05:42 AM
Subject: NT and Cornell V1.0 TCP problem

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>Hello,
> I am having trouble connecting to reflectors using version 0.96a17.
>I have NT4.0 with Service Pack 3 and the teardrop2 ICMP hotfix
>installed (I had this same problem without the hotfix installed). The
>system is connected to a LAN (which is not connected to the Internet)
>with an IP address of 10.0.0.4. I dial up to an ISP with a 56K modem
>when I want Internet connectivity.
> When I start up Cornell CU, on the bottom right of the CU window it
>reports an IP of 10.0.0.4. This happens even when I am connected to
>the Internet during CU startup. When I dial up a reflector, I get to
>the "select conference" screen but I cannot connect to the conference.
> I have this same problem with some reflectors (particulary on a
>EREF) when connecting with WP CU. Server reports error "Server error
>message: Your IP address is incorrect, restart CU-SeeMe
>Network (10.0.0.4) != Protocol (10.0.0.4)
>
>[ECU ID#:8283]"
> My first fix for this problem was to connect to a self-reflect
>conference on a WP reflector; this seemed to clear up the IP confusion
>for WP CU. It dosen't work for Cornell's latest version (or earlier
>versions).
> At first I thought that it was an IP binding order problem (I still
>do). Good old NT won't allow me to change the binding order for
>adapters - only protocols. Since TCP/IP is my only protocol, Windows
>will not allow me to change the binding order.
>
>Has anyone else experienced this problem? A fix? Or is it a
>"ctrl-alt-del - Microsoft has no plans to fill this hole - so you're
>on your own!" problem?
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