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multiple network adapters in NT

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16 replies

by osezer

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Hi,

We have a NT server. When we install a second NIC in IBM Server 220 (8645-220), a part of network falling down. So we can't see all of network clients in environment. What is wrong?

Thanks

16 replies

by cg it

First are some questions. Why are you installing a second NIC? What is the topology of your network? There really is insufficent information to provide an adequate answer.

by cg it

instead of using two nics, switch from hubs to switches [you will really see a difference in network response using switches] [traffic on the network go directly to the intended computer instead of all computers. substantially increases network response and decreases network load].

by cg it

As answer #2 mentioned, use TCP/IP protocol only [unless you have to use another].

by cg it

your switch at the backbone has to send network traffic [broadcast the traffic] to all computers contained on your LAN to find the intended recipient. [substantially slowing down your network waiting for a response from on the computers on the LAN].It can not send the traffic directly to the intended computer because your using hubs to connect your various clients. Hubs can not route network traffic to a particluar [intended] computer.

by osezer

Yes, you're right. But I think that, instead of using only one NIC if we use three NIC and connected three hubs, we can be faster.

by osezer

We have only one switch at backbone and we have three 16 port hubs which are connected to it. So we want to faster connect to the server we want to share network load.

by an_it_guy

Check if u are having multiple protocols installed on the Server. Make all your clients use a single network protocol, like TCP/IP, and remove all other protocols.
I had a similar problem, and this was it.
Cheers.

by curlergirl

I can't really tell for sure from your answers how your switches/hubs are connected. I think you should have your hubs each individually uplinked to the switch and then your server (both NICs) connected to the switch directly for best speed. This way, each hub can communicate fastest to the server through the switch, and each hub is a separate segment on the network, so there shouldn't be any drop off of clients connected to the network and fewer collisions. Is this how it's configured?

by osezer

We have only one NIC, connected to the switch. Each hub connected to the switch in separate segment. We want to add second NIC to the server, for to share network load.

by Member 25123508

If you do not have multiple network segments (lans connected via routers) then two adapters is not a good idea unless you have teaming software to allow the two nic's to work as a single interface. If you have two NIC's and two IP addresses for thesame machine, all you are doing to the network is creating more confusion and more chance for collisions and asynchronous routing via the two interfaces. This would actually slow things down instead of speeding them up (this was happening at my company before I was hired). This may account for not being able to see all the clients in the network as well.

by osezer

Yes we tried and see too. But why? We have a switch and three hubs. is this each hub a seperate segment?

by curlergirl

Ok - now I understand better what is going on. If you add a second NIC without teaming software (provided by some NIC manufacturers like 3COM on certain models), then each NIC has to have a separate IP address. Therefore, you are only adding traffic to your network, because your server now has to advertise two separate IP addresses, and your clients will try to reach the server on both addresses, instead of just one. This would cause more collisions and possibly cause some clients not to be able to find the server at all, depending upon the method of name resolution you are using. For example, if you are using DNS, you could potentially give the server an alias for one of the NICs, so that the server has two names. I'm not even sure how well that would work, not having really tried it, but theoretically it should. However, this really doesn't accomplish anything except make it necessary for you to use a different alias for certain network shares so that clients will look for thealias address instead of the regular one. I honestly don't see how that would speed things up at all. If you are using WINS, however, there's no way to control which IP address clients will get, or if they will get both and be totally unable to communicate with the server. If you really want to speed up your communication with the server, you would either have to team the NICs or get a gigabit network card, if you have a gigabit port on your switch. Hope this helps!

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