Choose which NIC is used for file transfers.

March 26, 2011 at 15:52:17
Specs: Windows XP SP3, 4gb
2 computers, 2 NICs in each computer.
Both computers connected to a router by 1 NIC each.
Second NICs in each system are wired together by a crossover patch cable.

Q. How do I tell the systems to send files to each other using the NICs with the crossover without sending through the router. Can it even be done?

I know how to do it using 1 NIC each but this is not the same.


See More: Choose which NIC is used for file transfers.

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#1
March 26, 2011 at 16:41:46
Windows is terrible at dual NICs, not to mention that there is no reason for it on a home system.

How do you know when a politician is lying? His mouth is moving.


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#2
March 26, 2011 at 16:52:56
I agree with guapo. There is no reason why both computers should not communicate through the router and have done with it, There is nothing to be gained by two having separate NICs,

Stuart


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#3
March 26, 2011 at 16:57:15
Well the reason for it is I have large quantity of files to transfer back and forth and the secondary nics are gigahertz nics. The router is only 10/100.

I also want to do it for the sake of doing it.

So don't concern yourself about the why, even if I only do it for a short time I still want to see if it can be done.

I can always disable the tcp/ip on the first nics for the duration but that is not the point.


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Related Solutions

#4
March 26, 2011 at 17:06:31
p.s.

Thats not saying guapo and Stuart are wrong, your both right as far as standard every day use.

But if you want to move 500gb back and forth a few times, going through a router still takes time compared to what I see a crossover doing.

Course, I could be wrong and maybe there is a fast way even when going through the router. I also have had speed issues with my router so the problem may be there.


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#5
March 26, 2011 at 18:00:06
If you only have two computers on this netwrok having a gigabyte connection between her two will confer vary little advantage,. The deciding factor is how quickly each computer can spew out the data and how quickly the other computer can receive, process and store it.

Just because your go from a 100 Mbs connection to a 1Gbs connections does not necessarily meant the data is going to be transfered any faster. 100 Mbs is more than most hard disks can keep up with over a sustained period, Gbs networks only come into there own when you have lots of computers all trying to use the networks simultaneously.

If there is a noticeable slow down going through the router then you need to be looking at the routers configuration. However, you have not given any statistics so it is all a bit guess work.

If you want to do it for the sake of doing it then that is a different thing altogether. Normally when a computer has two NIC they are bridged which connects one to the other which effectively does the same as the router.

Stuart


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#6
March 26, 2011 at 19:06:36
@Bob Martinez

You intension is comprehensible to me, because I had to copy several hundred gigabytes of data to another machine, as do you.
I started with 100 Mbit/s connection and stopped it, as I had time enough to think about it, during the copy job and it came to me, that both machines had 1 GBit LAN cards.

I used a crossover cable and connected both GBit cards, which was indeed much faster than on 100 MBit.

The difference is, that I had to do this only one time.
So maybe you can manage it by setting the priority in the settings of the network cards from automatically to manual and use a low priority of 1 for the GBit card and a higher priority for the 100 MBit card.
You might have to restart both computers after you've changed the settings, because it's windows.

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#7
March 27, 2011 at 02:20:28
Give the second NICs on each computer (the ones that are connected via the crossover cable) IP addresses on a subnet all to themselves. Then when specifying the file transfer, use that IP address when specifying the remote address. (If you want to use names rather than numeric IP addresses then put the appropriate entries in the hosts files on the computers.)

That way the computers will use the direct connection rather than going through the router.

You don't need to worry about routing or bridging or anything complicated like that; in fact it would be a disadvantage as you want the two networks - one to the router, the other private network between the two computers - to have no connection.


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#8
March 27, 2011 at 06:58:32
Bob: Don't forget that you have to consider how fast the PC can write data to the HD. It's just like special delivery in the post office. It might get to the destination post office quickly but the mailman might be a slow mover.

How do you know when a politician is lying? His mouth is moving.


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#9
March 27, 2011 at 07:45:02
I think you'll find that a hard disk can transfer data faster than a 100Mbit network even if you ignore any losses in the router.

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#10
March 27, 2011 at 12:55:43
No matter what, two NICs are a waste of time.

How do you know when a politician is lying? His mouth is moving.


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#11
March 27, 2011 at 13:28:22
Bob here is how you accomplish what you desire

The nics connected to the router should be getting dhcp ips from the router.
Do a ipconfig /all and note what that subnet range is [192.168.0 or1.x]

Give the two internal nics ip addresses like so they are in a different subnet
200.200.1.1 and 200.200.1.2
255.255.2550 for subnet mask
no gateway
no dns

On whatever computer share the folder you wish to be the distination.

Next map a drive letter to it but don't use host name but ip address like so

\\200.200.1.1\sharename
so to map it would be
net use z: \\200.200.1.1\sharename

When you transfer files to z: you will be using the crossover connection.

Sorry for all the forum negatve feedback. Must be a blue moon day.

Answers are only as good as the information you provide.
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#12
March 27, 2011 at 14:31:22
There was no negative feedback. It was reality feedback.

How do you know when a politician is lying? His mouth is moving.


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#13
March 27, 2011 at 14:39:59
@wanderer

How did you get internet access, when there is no default gateway configured?

If you do the mapping by using \\ip_address\shared_folder_name, it doesn't matter, whether there is default gateway or not.
When both NICs are in different subnets, and the GBit NICs are connected by crossover cable, the direction to the destination is clearly defined and the default gateway is not used to connect to the destination.

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#14
March 27, 2011 at 14:55:10
You don't need a gateway for the second NIC because there is no routing involved in that connection. Obviously you need a gateway for the other NIC as you need a route to the Internet.

This is all pretty standard stuff - it's a simple way to connect clustered computers for distributed computing.


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#15
March 27, 2011 at 17:21:10
@guapo
I am a pc tech and sometimes I must do things just for the sake of doing it. So that I learn how a thing works.
I did not know this until just now but there are motherboards with 2 nics built in so there is a reason in some cases to have more than 1 nic.
I believe that back before highend switches and whathave you it was fairly common to have multiNIC systems.
True, not in home use cases as you said but there are situations.

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#16
March 27, 2011 at 17:33:09
If you are doing it for experience & fun, go for it. I have nothing against that at all as long as you know that there really aren't any other benefits.

I didn't know about dual NICs on a motherboard. I imagine that it would give Windows some control over them. I'm not one of those kill MS guys but multiple NICs is one area that Unix & Linux have Windows beat.

How do you know when a politician is lying? His mouth is moving.


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#17
March 27, 2011 at 18:23:20
Man this question has certainly gotten a lot of attention.

@paulsep
I am not familiar with setting the priority of a network card so will have to look into that.

@ijack
How do I specify the file transfer as you put it?
Good points in your answer.

@wanderer
From what I know of networking and IP addresses, you seem to be on the right track for what I want to accomplish.

@All
I need to add some data....
Call the nics going to the router "NICSET1"
The Crossovers "NICSET2"
Both sets have entirely different ip adr and gateways.
System1 is the work computer.
System2 is the backup computer.
At the moment I have disabled tcp/ip on System2 NICSET1
So System2 only connects via NICSET2 to System1

I have seen a lot of different and maybe wrong ip settings for use with a crossover.
As I understand crossover IP settings, each nic IP setting is the other nic gateway.
This works.

System1
ip 192.168.1.1
mask 255.255.255.0
gate 192.168.1.2

System2
ip 192.168.1.2
mask 255.255.255.0
gate 192.168.1.1

Right away I lost my internet connection on System1. It seemed to not be able to decide which card to use. This may relate to setting priority mentioned by paulsep.

My workaround is to drop tcp/ip on both Systems NICSET2 and use NetBEUI, which I loaded a while back for other reasons on my XP systems.

Now I have fast file transfer and isolated System2 from any internet access.

But I still want to use tcp/ip.

Now I need to test what happens when I turn the NICSET1 on System2 back to tcp/ip available.

Will let you know how that turns out.

Any ideas in advance of the test are welcome.

Remember, this is not about what may be the smoothest way but about how to make it work.

This is the link to the dual NIC board I saw. Also has some interesting info on the crossover idea.

http://www.ghack.info/index.php?opt...


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#18
March 27, 2011 at 18:45:59
p.s.

What good has come of it?

The fastest file transfer attainable, all things being equal.
Security from the internet (I think, correct me if not so).
Other computers using the router are not affected (effected?) by any file transfers.

A bonus, I use a checksum file compare pgm to weed out duplicates and that was really slow when I compared a file on System1 to its counterpart on System2. This pgm allows me to compare whole directories and that can be a LOT of data with a LOT of file reads. Now it goes through files almost as fast as if they were all on the same hard drive.

But we still want to get the tcp/ip working, though the NetBEUI fix might actually be the best for the purpose.


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#19
March 27, 2011 at 19:16:45
At the NIC, used with crossover cable, you must not configure default gateway.
Only the NIC, used to connect to the internet needs to have configured a defautl gateway.

As wanderer stated, configure both NICs for different subnets.
If the router has an ip address of 192.168.1.1
Configure the NICs, that are needed to connect to the internet, on both systems, to get ip address automatically over DHCP from the router.

The NICs, used for crossover connection, should be configured manually.

System1 (work computer)
NICSET1
ip via DHCP (gets something like 192.168.1.100)
Subnet mask: 255.255.255.0
DNS: 192.168.1.1 (the router)
default gateway: 192,168.1.1 (also the router)

NICSET2
ip manually configured: 192.168.2.100
subnet mask: 255.255.255.0
no DNS (not needed)
no default gateway (not needed)

System2 (backup computer)
NICSET1
ip via DHCP (gets something like 192.168.1.101)
Subnet mask: 255.255.255.0
DNS: 192.168.1.1 (the router)
default gateway: 192,168.1.1 (also the router)

NICSET2
ip manually configured: 192.168.2.101
subnet mask: 255.255.255.0
no DNS (not needed)
no default gateway (not needed)

Then do map the drives by using it's ip address, e.g.:
\\192.168.2.101\shared_folder

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#20
March 27, 2011 at 23:44:44
By "specify the file transfer" I was referring to the file transfer method. For example, are you using a file share or FTP.

The gateway business is fairly straightforward. A gateway is exactly what it sounds like - a way of getting from one subnet to another (normally a router). For the connection between the two computers you don't need a gateway because only one subnet is involved. The computers will know about this pathway between them via entries in their routing tables (automatically created when the interface is created).

I'm bemused by the comments made by some that there is no advantage in doing what you ask, or say that Windows can't handle two NICs. This sort of setup is commonly used in situations where there is a need for fast communication between a small number of computers, and Winows handles it just fine. I've often set up servers this way.


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#21
March 29, 2011 at 08:13:43
@ijack
Ya one has to be careful about stating things in absolute terms, I'm positivily sure of that.

@ALL
I set NICSET2 to the same ip group 10.10.10.x as NICSET1 is set, just not in the zone the DHCP is providing.
Then remapped the shared drives using the ip addresses and it works. The only thing is that now it keeps asking me to confirm file copies.

Also, I have a networked printer with its own IP but now System1 wont print unless I disable NICSET2.

Subnet masks are the same on all devices right now.

Maybe when I print to the printers ip address it is trying to use NICSET2 and does not look any further than that.

Any ideas?

Would putting the NICs on different IPs help? Like....

NICSET1 10.10.10.x
NICSET2 192.186.1.x

Or different subnets? Right now it is standard 255.255.255.0 for everything.


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#22
March 29, 2011 at 09:37:03
Yes different subnets will help.
E.g.:
NICSET1 10.10.10.x / 255.255.255.0
NICSET2 192.168.1.x / 255.255.255.0

or

NICSET1 192.168.1.x / 255.255.255.0
NICSET2 192.168.2.x / 255.255.255.0

a.s.o.

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#23
March 29, 2011 at 11:51:29
Yes, the subnets must be different (although different subnets is what you actually called different IPs). Actually, you could use the same subnets as long as you put specific entries in the routing tables to specify which NIC to use when communicating between the two machines. But that's a pain - separate subnets is much easier.

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#24
March 29, 2011 at 14:52:50
Bob I layed out in post 11 a simple setup and explained why it had to be that way.

Yet you put gateway entries on both nic when I told you why not to.
You are asking about subnet masks that make no difference in your setup and should be just a plain class c.

I even showed you how to map a drive so you would use that connection.

Why haven't you done those things?

Here we are 13 post later.

Answers are only as good as the information you provide.
How to properly post a question:
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