Jake Posted February 25, 2007 Share Posted February 25, 2007 Is it possible to have two network cards in the same PC? (and them both working of course) Quote Link to comment Share on other sites More sharing options...
Ric Posted February 25, 2007 Share Posted February 25, 2007 i didnt think so myself Quote Link to comment Share on other sites More sharing options...
Pabs Posted February 25, 2007 Share Posted February 25, 2007 Yes it is. You can bridge the two cards together, if reqd. What do u need 2 cards for? EDIT: An example: If your broadband connection comes in and plugs into the network card, you can install another network card to link to another PC or hub/switch. You then bridge the two cards together making essentially 1 network, thus allowing anyone on the other end of the 2nd cable access to the internet. Quote Link to comment Share on other sites More sharing options...
Jake Posted February 25, 2007 Author Share Posted February 25, 2007 Well, I have 4meg NTL Cable broadband but my kids have Sky 2meg ADSL (Sky). Obviously when I'm connected to the NTL cable modem I can't connect to their network but I was thinking that maybe if I had 2 NICs I might be able to - and then I could copy that TomTom map to nipper's PC and Gerry could get the files from that PC Quote Link to comment Share on other sites More sharing options...
Steve Posted February 25, 2007 Share Posted February 25, 2007 Yes it is possible to have two cards. At work for our mail server we use one network card to connect to the Internet and one card to connect to the Main Server. Not the best way of doing it, but it works ok. Quote Link to comment Share on other sites More sharing options...
Bobbeh Posted February 25, 2007 Share Posted February 25, 2007 Yeah, or just buy a router and they can all connect to the one internet connection. Quote Link to comment Share on other sites More sharing options...
Jake Posted February 25, 2007 Author Share Posted February 25, 2007 I don't want them on my internet connection though, I want them to use the Sky one. They have a router and I can connect to it but I can't at the moment because I would lose my NTL connection. Ideally I'd like to use both the Sky and NTL at the same time on this PC but I'm told you need a special 'load balancing' router for that. Quote Link to comment Share on other sites More sharing options...
Pabs Posted February 25, 2007 Share Posted February 25, 2007 AFAIK you can't use both broadband connections on 1 PC, not without special routers etc. The best bet would be for you to keep it all seperate. For example - get ur second NIC in your PC, but do NOT bridge the network with your current connection. Do the same on the other PC. However, i've not set one up before, so that's about as much help as I can give Quote Link to comment Share on other sites More sharing options...
carl0s Posted February 25, 2007 Share Posted February 25, 2007 The two cards will work fine together. You'll want to make sure each network uses a different subnet; e.g. 192.168.0.0/24 for the first and 192.168.1.0/24 for the second, or 10.x.x.x. etc. Just so long as the network part is different (e..g the bit masked by the 255s in the subnet mask). You would then be in a situation where your machine doesn't know which to use for the internet, so, you could either manually configure your IP addresses, and leave out the default gateway on the interface that you *don't* want used for 'net, or, more properly, just set the Interface Metric (this means the 'cost' for using the interface). The lowest metric takes priority. So set the NIC which is connected to the Sky ADSL to 2 and set the preferred one to 1. I have to say I'm not sure if it would just work even if they were on the same subnet.. the machine might just send the ARP broadcasts out of both NICs and therefore still find a machine whether it's on NIC1 or NIC2, but for simplicity I'd say make sure they're on different subnets. Quote Link to comment Share on other sites More sharing options...
carl0s Posted February 25, 2007 Share Posted February 25, 2007 It's quite a normal thing to have multiple network cards, it's known as being 'multi homed'. Just think of a router/firewall, or an MS Windows machine running ISA Server. It would have probably three network cards : 1 connecting to the internet, one connecting to the private LAN, and one connecting to machines in a DMZ, i.e. machines which are accessible to the outside world (webservers etc.) Quote Link to comment Share on other sites More sharing options...
Pabs Posted February 25, 2007 Share Posted February 25, 2007 out of interest, carl0s, how do you set the Interface Metric?? Quote Link to comment Share on other sites More sharing options...
chilli Posted February 25, 2007 Share Posted February 25, 2007 you can have as many cards as you want in a machine, so long as they don't conflict. as carlos points out above for firewalls and routers, my own firwall has 3 cards in it no problems. use routing entries/default gateways to ensure traffic flows as you want it, easy peasy really Quote Link to comment Share on other sites More sharing options...
carl0s Posted February 25, 2007 Share Posted February 25, 2007 out of interest, carl0s, how do you set the Interface Metric?? It's in the TCP/IP preferences for each interface. Quote Link to comment Share on other sites More sharing options...
Jake Posted February 25, 2007 Author Share Posted February 25, 2007 So why can't I use two NICs with two different ISPs then? Quote Link to comment Share on other sites More sharing options...
chilli Posted February 25, 2007 Share Posted February 25, 2007 using the interface metric does have characteristics worth knowing, for example if your higher priority (lower cost) card becomes unavaliable, traffic will take the next path - if that is undesirable (often it is) then it's best not to rely on this. Cost for routing is typically for when there are several alternate routes between the same endpoints. AFAIK anyway, just so you are aware Quote Link to comment Share on other sites More sharing options...
Schtuv Posted February 25, 2007 Share Posted February 25, 2007 So why can't I use two NICs with two different ISPs then? At a guess because both want to be the default route for all non local traffic. Are you trying to load balence between them? Quote Link to comment Share on other sites More sharing options...
chilli Posted February 25, 2007 Share Posted February 25, 2007 So why can't I use two NICs with two different ISPs then? Well in theory you could, but you would need a routing protocol in order to make sense of the routes properly. Something like ospf for example or bgp However I don't think ISPs would give you access to that for obviously reasons, you are an end point not an ISP yourself... That's my understanding anyway, could be talking bollox again of course lol Quote Link to comment Share on other sites More sharing options...
Branners Posted February 25, 2007 Share Posted February 25, 2007 maybe Im wrong here, but if the machines are all on the same network could you not just set their default gateway as being the ADSL router and your default gateway as the NTL router? JB Quote Link to comment Share on other sites More sharing options...
chilli Posted February 25, 2007 Share Posted February 25, 2007 Well, I have 4meg NTL Cable broadband but my kids have Sky 2meg ADSL (Sky). Obviously when I'm connected to the NTL cable modem I can't connect to their network but I was thinking that maybe if I had 2 NICs I might be able to - and then I could copy that TomTom map to nipper's PC and Gerry could get the files from that PC sorry all that waffle but I hadn't tried to help with your original problem, which should be easy to solve. Arrange your local network with a private network address, like a 192.168.0/24 class c add a static route for the private network to use the ethernet card for the private network, on yor machine do the same type of thing for the other private machines so they can reply and that is it! providing i understand what you want to do properly static routes will overide default gateways, this is quite a common setup and i have a similar thing here Quote Link to comment Share on other sites More sharing options...
carl0s Posted February 25, 2007 Share Posted February 25, 2007 maybe Im wrong here, but if the machines are all on the same network could you not just set their default gateway as being the ADSL router and your default gateway as the NTL router? JB That'd probably be the easiest solution all round, no need for additional NICs, but I suspect Jake is connecting directly to the cable modem rather than through a router, so he's being given a public IP by the modem and therefore can't do that. Quote Link to comment Share on other sites More sharing options...
chilli Posted February 25, 2007 Share Posted February 25, 2007 yes, set default gateways but you will need some routes for private networks to communicate, unless they are all on the same local network, in which case there shouldn't be anything to do anyway? lol Quote Link to comment Share on other sites More sharing options...
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