Small Office Networking help required

giggsirish

Hi Guys - wondering if someone could offer me some help on below setup.

Currently have 4 PC's networked through a 3Com hub. All 4 have static IP addys 192.268.1.2/3/4/5 and a subnet of 255.255.255 and gateway of 192.268.1.254

None have internet access and all have access to shared folders on each of the other PC's

I need to allow one of these PC's (just one) internet access through an eircom router. Problem is how? Can I simply add a second NIC or wireless USB fob and connect it to the eircom router. If so what do I do about IP addressing? The eircom routers also use 192.168.1.x and how do I force this 1 PC to use ist 2nd NIC or wireless fob to connect to the router for internet browsing


Any help would be most welcome.

Dardania

the simplest solution would be to put all PCs in the IP range 192.168.x.y, but for the PC that needs net access, give it the netopia's IP 192.168.1.254 for DNS & Gateway.

giggsirish

Dardania wrote: »

the simplest solution would be to put all PCs in the IP range 192.168.x.y, but for the PC that needs net access, give it the netopia's IP 192.168.1.254 for DNS & Gateway.

Thanks Dardania. Forgive my ignorance but does this mean connecting the router by cable to the hub? Is there any way to work it by making use of a second NIC on the PC? Also as the PC's will have static IP's how do I allow the eircom router remain in DHCP mode (to assign IP's to any visitors laptop or iphone etc while reserving the IP's I need for the 4 static PCs.

I need as secure an option as possible. 4 networked PC's but strictly only one that also has internet access. All 4 will be running AVG Business Edition and the 3 with no internet will get their updates from the one with internet access from a repository.

Current setup on NIC1 (connected to hub)of PC I need to give internet access:
IP:192.168.1.1
Subnet: 255.255.255.0
Default Gateway:192.168.1.254
Preferred DNS: 192.168.1.254

What settings do I need to give the second NIC (to be connected to Eircom router) to allow it route only internet traffic through this NIC? Can I change the Eircom router to a subnet of 255.255.254.o and IP ranges of 192.168.2.x?

Dardania

Hi giggsirish,

You can either connect the router by ethernet cable to the hub, or you can plug all of the PCs into the router's - it won't make any difference to the configuration that only the PC with the gateway & DNS servers configured will be able to connect to the outside world.

Leave the DHCP option running on the router, then any visitors will automatically get access

giggsirish

Hi Dardania,

Many thanks. If possible I would like to leave the current Networked as it is and use a second NIC if possible for internet access. Will just start connecting it up and see how I go.

Thanks again for the help.

mickoneill30

Would it not be handier to just remove the default gateways (192.268.1.254) from all the machines that don't need internet access.

If there's no default gateway anything that tries to go to the internet won't know where to go.

Edit: Ah basically the same as Dardanias first suggestion. Sorry Dardania, I should read posts properly.

giggsirish

Hi Mick,

I want 3 of the PC's to have no connection to the broadband router. Is this not the safest option? If I remove the default gateway from the 4th PC. Add a second NIC. Give the second NIC the gateway of the broadband router will this make me good to go? The current network and all static shares between PC's remain the same and the 4th PC has best of both. Internet and network.

Again my networking is not the best so forgive me if im being stupid here.

mickoneill30

giggsirish wrote: »

Hi Mick,

I want 3 of the PC's to have no connection to the broadband router. Is this not the safest option?

Yep it's safer. But to me it's safer like plugging out the network cable is safer. You can do it but why?

giggsirish wrote: »

If I remove the default gateway from the 4th PC. Add a second NIC. Give the second NIC the gateway of the broadband router will this make me good to go? The current network and all static shares between PC's remain the same and the 4th PC has best of both. Internet and network.

That'd work. I can't see the benefit though. You're just sending the internet traffic out through a different NIC. The other machines are on the same subnet with no defaut gateways anyway.

If the two NICs are on different subnets and only the second subnet can access the internet then there's some security but I don't think that's what you're doing (you'd need a second router / firewall).

giggsirish

Hi Mick,

Yes safety is the most important part. Only one PC with any exposure to the outside world (or it to them)if possible.

I have attached a pdf of what I have and what I need. Will show it a lot better than any text I can write.

All PC's will have antivirus software updating from repository on the Internet enabled PC and the internet enabled PC will have a software firewall (which I hope is enough along with the eircom routers internal firewall)

mickoneill30

Ah. That hub helps. All 4 internal NICs can be on a totally seperate subnet. Then the 5th NIC can use the Eircom settings.

giggsirish

mickoneill30 wrote: »

Ah. That hub helps. All 4 internal NICs can be on a totally seperate subnet. Then the 5th NIC can use the Eircom settings.

Hi Mick, So am I correct in saying:

Leave current network as it is.

On the PC with second NIC connected to eircom router:

Change eircom router to a subnet of 255.255.254.0?

Do I need to remove the gateway entry from the NIC connected to network and only have one gateway entry on NIC connected to router?

Thanks for the help. Much appreciated.