Fighting NICs

  • Thread starter Thread starter Overlord
  • Start date Start date
O

Overlord

How goes it all?
Just looking for a clue or two here.
I can build ya whatever ya like but networking isn't my forte.
Here's the deal:
2 NICs in the system
First is connected to the Cable modem and works fine.
Second NIC is connected to a wireless router that gives me access to
my son's computer in his room. It works great too.

When I say they work great, they do - ALONE.

When I had the first NIC in alone, I could smurf the internet at just
about the limits of my account cap (like 2950kbps). Added the second
NIC and router and fiddled with it a while. Finally got good fast
access to my son's system.... at the expense of my Internet access on
the first NIC. Disabled the second NIC and boom, instant Internet
access. Seems I can get what I want from either NIC at the expense of
the other's functionality.
I can surf with the second NIC disabled and no wireless access to my
son, or I can access my son's system by enabling the second NIC but it
murders the functionality of my first NIC.

Is the router stealing my IP address?
Any ideas?
~~~~~~
Bait for spammers:
root@localhost
postmaster@localhost
admin@localhost
abuse@localhost
postmaster@[127.0.0.1]
(e-mail address removed)
~~~~~~
Remove "spamless" to email me.
 
How goes it all?
Just looking for a clue or two here.
I can build ya whatever ya like but networking isn't my forte.
Here's the deal:
2 NICs in the system
First is connected to the Cable modem and works fine.
Second NIC is connected to a wireless router that gives me access to
my son's computer in his room. It works great too.

When I say they work great, they do - ALONE.

When I had the first NIC in alone, I could smurf the internet at just
about the limits of my account cap (like 2950kbps). Added the second
NIC and router and fiddled with it a while. Finally got good fast
access to my son's system.... at the expense of my Internet access on
the first NIC. Disabled the second NIC and boom, instant Internet
access. Seems I can get what I want from either NIC at the expense of
the other's functionality.
I can surf with the second NIC disabled and no wireless access to my
son, or I can access my son's system by enabling the second NIC but it
murders the functionality of my first NIC.

Is the router stealing my IP address?
Any ideas?
Click to expand...

Connect the router to the cable modem. Connect your computer (wired) and
your son's computer (wireless) to the router. It sounds like you physically
have an incorrect configuration. It also sounds from your description that
you are using ICS and a router. With the router you do not use ICS. Check
out these sites for configurations.

http;//www.practicallynetworked.com
http://www.homenethelp.com
http://www.wown.com

And, there should be configuration descriptions available in your router's
manual or the router vendor's web site.
 
Kurt,

Couple of quick question:

What OS are you using on both computers and what are the
ip addresses for the first and second NIC, the wireless
router and your son's computer.

Michael
 
Kurt,

Couple of quick question:

What OS are you using on both computers and what are the
ip addresses for the first and second NIC, the wireless
router and your son's computer.
Click to expand...
Main system that the cable modem is connected to is Win2K pro.
My son is running <cough!> ME.

Interesting thing is that apparently I can kill the firewall, then enable 2nd NIC, and everything is
fine. Putting the firewall back up doesn't affect the system operation then. Wondering if the
router is trying to register my son's system on Cox's DNS server or something.
Windows 2000 IP Configuration

Host Name . . . . . . . . . . . . : colossus
Primary DNS Suffix . . . . . . . :
Node Type . . . . . . . . . . . . : Broadcast
IP Routing Enabled. . . . . . . . : No
WINS Proxy Enabled. . . . . . . . : No
DNS Suffix Search List. . . . . . : dl.cox.net

Ethernet adapter Local Area Connection 2:

Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Network Everywhere Fast Ethernet Adapter(NC100 v2)
Physical Address. . . . . . . . . : 00-04-5A-53-DF-2A
DHCP Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
IP Address. . . . . . . . . . . . : 192.168.0.101
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Default Gateway . . . . . . . . . : 192.168.0.1
DHCP Server . . . . . . . . . . . : 192.168.0.1
DNS Servers . . . . . . . . . . . : 192.168.0.1
Lease Obtained. . . . . . . . . . : Wednesday, November 26, 2003 9:34:44 AM
Lease Expires . . . . . . . . . . : Wednesday, December 03, 2003 9:34:44 AM

Ethernet adapter Internet Connection:

Connection-specific DNS Suffix . : dl.cox.net
Description . . . . . . . . . . . : Broadcom NetXtreme Gigabit Ethernet
Physical Address. . . . . . . . . : 00-0C-6E-06-87-67
DHCP Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
IP Address. . . . . . . . . . . . : 68.106.71.155
Subnet Mask . . . . . . . . . . . : 255.255.254.0
Default Gateway . . . . . . . . . : 68.106.70.1
DHCP Server . . . . . . . . . . . : 172.19.25.13
DNS Servers . . . . . . . . . . . : 68.1.208.245
68.1.208.30
68.2.16.30
Lease Obtained. . . . . . . . . . : Wednesday, November 26, 2003 8:47:01 AM

Probably not a good idea to put all this in here but I don't generally even let Cox ping me.....
Michael
Click to expand...
~~~~~~
Bait for spammers:
root@localhost
postmaster@localhost
admin@localhost
abuse@localhost
postmaster@[127.0.0.1]
(e-mail address removed)
~~~~~~
Remove "spamless" to email me.
 
Connect the router to the cable modem. Connect your computer (wired) and
your son's computer (wireless) to the router. It sounds like you physically
have an incorrect configuration. It also sounds from your description that
you are using ICS and a router. With the router you do not use ICS. Check
out these sites for configurations.

http;//www.practicallynetworked.com
http://www.homenethelp.com
http://www.wown.com

And, there should be configuration descriptions available in your router's
manual or the router vendor's web site.
Click to expand...
It's a D-Link router. I already know it wants to be in charge of the access.
The site's configurations and in fact the install disk/utils are spectacularly unhelpful
for my use of it. Some time I may put it where it wants to go and take advantage of it's
hardware firewall/NAT etc, but for the moment it goes where I say it goes.
Since I can fire it up, kill the firewall, enable the second NIC, raise the firewall and everything
runs fine, I'm wondering what that connection could be now....

~~~~~~
Bait for spammers:
root@localhost
postmaster@localhost
admin@localhost
abuse@localhost
postmaster@[127.0.0.1]
(e-mail address removed)
~~~~~~
Remove "spamless" to email me.
 
(e-mail address removed) (Overlord) wrote in @news.central.cox.net:
How goes it all?
Just looking for a clue or two here.
I can build ya whatever ya like but networking isn't my forte.
Here's the deal:
2 NICs in the system
First is connected to the Cable modem and works fine.
Second NIC is connected to a wireless router that gives me access to
my son's computer in his room. It works great too.

When I say they work great, they do - ALONE.

When I had the first NIC in alone, I could smurf the internet at just
about the limits of my account cap (like 2950kbps). Added the second
NIC and router and fiddled with it a while. Finally got good fast
access to my son's system.... at the expense of my Internet access on
the first NIC. Disabled the second NIC and boom, instant Internet
access. Seems I can get what I want from either NIC at the expense of
the other's functionality.
I can surf with the second NIC disabled and no wireless access to my
son, or I can access my son's system by enabling the second NIC but it
murders the functionality of my first NIC.

Is the router stealing my IP address?
Any ideas?
~~~~~~
Bait for spammers:
root@localhost
postmaster@localhost
admin@localhost
abuse@localhost
postmaster@[127.0.0.1]
(e-mail address removed)
~~~~~~
Remove "spamless" to email me.
Click to expand...

As BobC said, it's physically incorrect, or more precisely, configured
incorrectly for the setup you have chosen.

For perfect results, all the time, the cable modem should be connected to
the router, and the wired PC to the router.

It took a little thinking after looking at your etherent setting's from
your later post, but your physical configuration should work with some
TCP/IP configuration changes.

First, on the rtr, disable DHCP and set the PC's to static addresses. Since
the rtr is assuming it's doing NAT to the internet, which it's not, it is
DHCP'ing it's own IP to both PC's for the 'Default Gateway'. If you don't
know what the default gateway is, and I assume you don't, the default
gateway is the interface all packets are forwarded to if the destination is
not on the local LAN. In your case, your LAN subnet is 192.168.0.0/24. When
a packet is destined for say 24.48.33.2, this is not your subnet, it sends
it out to the default gateway. When you disable the second NIC, there's
only one gateway, the Cox cable connection, so it knows where to send it
and you have no problem. When you have the second NIC enabled, the PC has 2
default gateways, your Cox IP, and 192.168.0.1, the IP of the rtr. Windows
will get confused and send it out either gateway, not one specific gateway.

On the laptop, it is also getting 192.168.0.1 as the default gateway, which
is wrong, because the default gateway of the laptop should be your 2nd NIC,
192.168.0.101.

When you turn off then on the firewall, that firewall picks up everything
and seems to straighten it out.

To verify this before changing over your physical connection to the way
it's designed to be used try this.

On the desktop, open a command prompt.
Type: route print <press enter>
You should see 2 routes with a destination of 0.0.0.0, these are the
default routes.
Type: route delete 0.0.0.0 <return>, which will delete both of them
Then type: route add 0.0.0.0 mask 0.0.0.0
Now the desktop is set right.

On the laptop:
open a command prompt
route delete 0.0.0.0
route add 0.0.0.0 mask 0.0.0.0 192.168.0.101

Now it SHOULD work, if this was the problem, assuming that ICS, which I
don't have any experience (or use) for, doesn't screw up basic IP
principles.

Since you have the router, you might as well be using it. You will get much
better performance using RISC processor hardware dedicated to doing one
task, than using a Microsoft OS loaded PC to do NAT. In addition to the
programs your are running, the 20 or 30 or so Win2K services running, and
most likely lower end NICs, making it do ICS on a broadband connection when
you have the routing hardware already, is, well.......stupid.

Oh yeah, doing DHCP on a wireless router is a security risk, and, I hope
you enabled encryption and choked down wireless access by MAC address.
Granted you may not have sensitive info on your PC, but that doesn't mean
someone else can't use you broadband connection for malicious intent.
 
Back
Top