2 LAN Cards (XP Pro)

[Matz]

Hi, just thought I would post this to glean ideas / thoughts etc.

I have a machine fitted with 2 LAN Cards. One is connected to the company network, and one connected to a dedicated router for Broadband (bypassing proxys and corporate firewalls etc - used for VPN testing purposes amongst other things).

How do i configure this as a router, so for instance I can connect remotely to the machine via XP Remote Desktop over the Company LAN, but set the machine up so that is has no internet connection only via the Broadband line.?

I think it should be as simple as setting the proxy in LAN Settings for internet explorer to the LAN Card IP connected to the Broadband router? I do now want any access to the company LAN from the BB Lan and vice versa. I only want to be able to remote desktop to it.

If necessary I can leave the Machine off the comapny LAN, and use as a stand alone tesing unit, but ideally I think I should be able to set up a functioning, safe and secure set up with 2 LAN Cards.

Any thoughts? Has anyone a similar set up?

[StuartR]

Scroll down this article to the section titled Windows XP Network Bridge and see if it helps.

StuartR

[StuartR]

Woops,

I didn't read carefully enough.

I think you may get what you want by just setting your default gateway to point to the dedicated router, and then setting specific routes to your company network over the other connection. Look at the syntax for the ROUTE command to get you started.

StuartR

[Matz]

Thanks for this StuartR, I will look into using the ROUTE command as you say.

What i DONT want is for anything to be able to pass from the one to the other.

[StuartR]

Then you definitely don't want to set up a network bridge.

Start with a Route Print command to find the current routes (print this out to use as a reference when you mess everything up).
Then use a combination of Route Delete and Route Add commands to set the routes you want.

StuartR

[Matz]

Thanks StuartR.

I wont be able to set this up till New Year, so I will get it running and see what the ROUTE command offers...

I may post back if I get a little stuck, just to check your thoughts!

Have a good Christmastime and Peaceful New Year. <img src=/S/munch.gif border=0 alt=munch width=19 height=17>

matz

[Matz]

Ok, so I have connected to the Broadband via wireless, and am connected to the Corporate LAN via the LAN Port.

I set the LAN port to a static IP on the company LAN, with NO DEFAULT GATEWAY, which i thought would help prevent traffic crossing over.
I left the Wireless LAN to pick up its IP via DHCP so it gets the default gateway etc.

When I do a ROUTE PRINT I get the following:

<pre>Documents and SettingsAdministrator>ROUTE PRINT
================================================== =========================
Interface List
0x1 ........................... MS TCP Loopback interface
0x3 ...00 0f 1f be 33 80 ...... Broadcom 570x Gigabit Integrated Controller -
terministic Network Enhancer Miniport
0x90002 ...00 90 96 ce ba ac ...... Dell Wireless 1350 WLAN Mini-PCI Card - De
rministic Network Enhancer Miniport
================================================== =========================
================================================== =========================
Active Routes:
Network Destination Netmask Gateway Interface Metric
0.0.0.0 0.0.0.0 192.168.1.254 192.168.1.65 25
99.99.99.0 255.255.255.0 99.99.99.199 99.99.99.199 20
99.99.99.199 255.255.255.255 127.0.0.1 127.0.0.1 20
3.255.255.255 255.255.255.255 99.99.99.199 99.99.99.199 20
127.0.0.0 255.0.0.0 127.0.0.1 127.0.0.1 1
192.168.1.0 255.255.255.0 192.168.1.65 192.168.1.65 25
192.168.1.65 255.255.255.255 127.0.0.1 127.0.0.1 25
192.168.1.255 255.255.255.255 192.168.1.65 192.168.1.65 25
224.0.0.0 240.0.0.0 99.99.99.199 99.99.99.199 20
224.0.0.0 240.0.0.0 192.168.1.65 192.168.1.65 25
255.255.255.255 255.255.255.255 99.99.99.199 99.99.99.199 1
255.255.255.255 255.255.255.255 192.168.1.65 192.168.1.65 1
Default Gateway: 192.168.1.254
================================================== =========================
Persistent Routes:
None</pre>



Should I be able to tell from looking at this that no traffic from one card can get through to the other?

[StuartR]

Your routing table looks about right to me, and if you haven't enabled any gateway software then you won't normally route traffic from one network to the other.

If your PC gets hacked and somebody installs their own software then they can route packets between networks, which is why my employers forbid us from configuring PCs like this.

StuartR

[Matz]

Hi Stuart. Thanks. I understand the hacking issue and will not keep this as a permanent 'always on' solution. More as a backup/standalone PC.

Regards remote desktop, when i connect to the PC I enable the network card to the Broadband connection when I need to use it and keep it disabled otherwise. The router has a firewall and there is also firewall software on the PC.

Do you think this is still a high risk? i do not want to compromise security. It may be best to forfeit the remote desktop idea and keep the Broadband PC stand alone off the LAN.

Cheers

[StuartR]

It's probably not high risk, but you need to have good quality antivirus and antispyware products, and to practice "safe computing"1 to make sure that it is low risk.

StuartR

1Safe Computing = not visiting gambling and pornography web sites, not clicking links in email messages, not opening attachments that you aren't very very sure are safe etc.