Can a PC connect to two networks simultainiously

Discussion in 'Hardware' started by Tueur, Dec 20, 2011.

  1. Tueur

    Tueur Sergeant Major

    Hi There,

    I am a relative network novice and need some help with a setup at work. I have recently inherited and a LAN made up of about 15 PCs which as far as security goes is woefully out of date. There are a couple of PCs with server 2003 and the rest are running XP. it is a closed LAN with not outside internet connection. We do have a broadband connection but that is only used for a VPN connection to software supliers. We recently had a virus outbreak which I have managed to clean up and I am now looking at patching the system and getting AV on.

    So... We are currently trialing NOD32 Business and I am trying to sort out getting updates.

    The main LAN has a Cisco Switch linking all the PCs together with Static IPs. They arent standard local IPs as they begin 10.x.x.x. We have another Small LAN which I am not managing which has a couple of PCs connected by CAT5 to a BT wireless router with an internet conection and DHCP. We have a spare laptop running XP which has a wireless NIC and a cable NIC... So I want to use the cabled connection onto my LAN and configure static IPs then use the wireles connection to connect to the BT router for internet access. I then want to sent up the a NOD32 mirror service so that it downloads the updates through the BT router and store them on the mirror on the laptop. These are then accessed on the LAN from all the other PCs.

    I dont think I can bridge the connections as they use different IP ranges. Aside from this I dont really want to bridge the connections as I dont want the LAN to have internet access and I dont want any comunications between the two networks other than the laptop that is acting as the "bridge"

    Any advice appreciated.

    Cheers guys
     
  2. djlowe

    djlowe Private First Class

    Hi,

    Based on the setup as you've described, I think that your best bet is this: Assuming that the laptop has a PCMCIA/PC Card/ExpressPort slot, invest in an Ethernet NIC for it.

    Connect the built-in Ethernet port to the Cisco switch, assigning it an IP that is on that subnet. Leave the default gateway empty.

    Connect the new Ethernet adapter to the other network, assign it a static IP that falls outside the DHCP pool on it, AND doesn't conflict with any currently-assigned IP addresses - make sure all servers, printers, etc. on that side are up, select an IP, ping it from a computer on that side to be sure there's nothing at that address.

    Make sure its default gateway points to the router that has an Internet connection.

    At that point, you have a laptop that is connected to both networks. Since it only has Internet access on one adapter, the OS will use that to get NOD32 updates.

    By default, there will be no bridging of traffic between the two.

    Configure RDP on the laptop to allow you remote access to it from either LAN, and only give yourself access.

    Then you can RDP to the laptop, get the updates, and do whatever you wish, including pointing the computers on the 10.x.x.x network to it on that side as an update server.

    Hope this helps!

    Regards,

    dj
     
  3. djlowe

    djlowe Private First Class

    That should be "routing", of course!

    Regards,

    dj
     
  4. Tueur

    Tueur Sergeant Major

    Thanks for the reply. That is kind of what I have done. Didnt bother a PCMCIA NIC but used the built in wireless card to connect to net with DHCP IP. I have set a folder on the laptop to be a network share. The laptop downloads the updates and saves them in the shared folder. The client PCs then pick up the updates from the share. I have set the laptop to wake on lan and then cary out all the updates then it shuts down once complete. All in all the networks are only connected for about half hour over night.
     

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