Multiple network cards

[risingflight]

Hello i have one windows 7 computer with 3 network cards connected.

I have assigned ip addresses to 3 network cards but i am able to ping to only one ip.
I am not able to ping to other 2 network cards ip addresses. how do i achieve it.

 

[Shadowjk]

What are the 3 IP addresses? Are they connected to the same switch/IP subnet? An ipconfig would be good to see. It sounds like the addresses might be incorrectly configured and the client accidently sending the traffic to its default gateway.

Many Thanks,
Josh

 

[risingflight]

Three Network Cards are on the same subnet with Same IP Address Scheme

 

[Shadowjk]

I need more information in order to better assist you. Are you saying that each NIC his the same IP address? Or that they have 3 separate addresses?

Also, firewalls can sometimes block ICMP (Ping) traffic if the NIC is seen as public. Try to temporarily disable the firewall and try again

Many thanks,
Josh

 

[chev65]

This certainly works for me but in my case it's two different IP's and both are active connections, wired/wireless are both connected to the internet, of course Windows is only using one of those connections at a time but I'm able to ping both of them without problems.

I use a group policy that allow Windows to connect to both at start up.

 

[Shadowjk]

This certainly works for me but in my case it's two different IP's and both are active connections, wired/wireless are both connected to the internet, of course Windows is only using one of those connections at a time but I'm able to ping both of them without problems.

I use a group policy that allow Windows to connect to both at start up.

Have you changed the metrics in the local routing table for any of the interfaces? From a routing perspective the issue may be where the return traffic is sent out a different interface (And Source IP address) than what it was received on due to Windows picking the better interface. This would cause the reply traffic to fail on the client end since source IP addresses would not match.

On routers this can be an issue and is mitigated with certain security measures however considering that this is a Windows machine I am not entirely sure if the same concept applies. I would still be convinced with the firewall being the issue since the other NICs are most likely seen as "Public Interfaces".

Josh

 

[chev65]

This certainly works for me but in my case it's two different IP's and both are active connections, wired/wireless are both connected to the internet, of course Windows is only using one of those connections at a time but I'm able to ping both of them without problems.

I use a group policy that allow Windows to connect to both at start up.

Have you changed the metrics in the local routing table for any of the interfaces? From a routing perspective the issue may be where the return traffic is sent out a different interface (And Source IP address) than what it was received on due to Windows picking the better interface. This would cause the reply traffic to fail on the client end since source IP addresses would not match.

On routers this can be an issue and is mitigated with certain security measures however considering that this is a Windows machine I am not entirely sure if the same concept applies. I would still be convinced with the firewall being the issue since the other NICs are most likely seen as "Public Interfaces".

Josh

My firewall doesn't block any ping requests on either of my network interfaces despite having them both working with different IP's at the same time. No need to change the metric in my case, the entire metric thing is overrated and inconsistent at best.

I can only guess that the Op may be trying to ping those IP's outside of the gateway's subnet which won't work without some type of routing set up.

In case you were wondering about the GPO setting, Windows will not consistently connect to both interfaces at start up like it does now, unless that setting is disabled. I just use the wireless for testing.

Both of my connected interfaces with different IP's showed no delay or dropped packets with the ping, that was the only point I was trying to make.

 

[Shadowjk]

This certainly works for me but in my case it's two different IP's and both are active connections, wired/wireless are both connected to the internet, of course Windows is only using one of those connections at a time but I'm able to ping both of them without problems.

I use a group policy that allow Windows to connect to both at start up.

Have you changed the metrics in the local routing table for any of the interfaces? From a routing perspective the issue may be where the return traffic is sent out a different interface (And Source IP address) than what it was received on due to Windows picking the better interface. This would cause the reply traffic to fail on the client end since source IP addresses would not match.

On routers this can be an issue and is mitigated with certain security measures however considering that this is a Windows machine I am not entirely sure if the same concept applies. I would still be convinced with the firewall being the issue since the other NICs are most likely seen as "Public Interfaces".

Josh

My firewall doesn't block any ping requests on either of my network interfaces despite having them both working with different IP's at the same time. No need to change the metric in my case, the entire metric thing is overrated and inconsistent at best.

I can only guess that the Op may be trying to ping those IP's outside of the gateway's subnet which won't work without some type of routing set up.

In case you were wondering about the GPO setting, Windows will not consistently connect to both interfaces at start up like it does now, unless that setting is disabled. I just use the wireless for testing.

Both of my connected interfaces with different IP's showed no delay or dropped packets with the ping, that was the only point I was trying to make.

Hmmm... Fair enough

The OP didn't say where they were pinging from so I just assumed from the same subnet . You might have discovered something there but only time can tell.

From a server perspective I find multiple layer 3 interfaces rarely used productively due to their inability to fail over and non bandwidth increasing nature. It is typical to have the NICs bundled to increase bandwidth and assign one IP address to aggregated link.

Josh

 

[chev65]

Have you changed the metrics in the local routing table for any of the interfaces? From a routing perspective the issue may be where the return traffic is sent out a different interface (And Source IP address) than what it was received on due to Windows picking the better interface. This would cause the reply traffic to fail on the client end since source IP addresses would not match.

On routers this can be an issue and is mitigated with certain security measures however considering that this is a Windows machine I am not entirely sure if the same concept applies. I would still be convinced with the firewall being the issue since the other NICs are most likely seen as "Public Interfaces".

Josh

My firewall doesn't block any ping requests on either of my network interfaces despite having them both working with different IP's at the same time. No need to change the metric in my case, the entire metric thing is overrated and inconsistent at best.

I can only guess that the Op may be trying to ping those IP's outside of the gateway's subnet which won't work without some type of routing set up.

In case you were wondering about the GPO setting, Windows will not consistently connect to both interfaces at start up like it does now, unless that setting is disabled. I just use the wireless for testing.

Both of my connected interfaces with different IP's showed no delay or dropped packets with the ping, that was the only point I was trying to make.

Hmmm... Fair enough

The OP didn't say where they were pinging from so I just assumed from the same subnet . You might have discovered something there but only time can tell.

From a server perspective I find multiple layer 3 interfaces rarely used productively due to their inability to fail over and non bandwidth increasing nature. It is typical to have the NICs bundled to increase bandwidth and assign one IP address to aggregated link.

Josh

Yes those servers also have Network Teaming software built into them that allow this NIC bundling. Someone made a post not long ago showing the results.

Back in the Vista days they had Network Teaming software built into the drivers for my NVidia board but it never really worked as advertised.

It seems to work much better with the new server software where you can aggregate a few Gb NIC's and actually increase bandwidth. Some more info about this in the link.

Of course the Op never said anything about teaming but it's an interesting subject just the same.

http://www.sevenforums.com/network-...tion-bandwidth-doubling-2pcs-2-nics-each.html

 

[Shadowjk]

Aye, I found it a cool topic when using my college's lab! Plus I can configure LACP or PAgP on the switch to get the maximum benefits which isn't something I can do at home without emulation software. Then it just becomes a matter of knowing the configuration rather than using the benefits

Josh

 

[chev65]

Aye, I found it a cool topic when using my college's lab! Plus I can configure LACP or PAgP on the switch to get the maximum benefits which isn't something I can do at home without emulation software. Then it just becomes a matter of knowing the configuration rather than using the benefits

Josh

NIC teaming, great subject for college lab experiments.

You can see at the link it actually works to increase bandwidth which is kind of cool. I guess the tricky part is setting up the switch so you can enable LACP mode on the teaming interface.

Server 720 - Server 2012 R2 Blog: SMB 3.0 Multipath over Nic Team in Windows Server 2012

 

[Shadowjk]

The hashing algorithms end up being the headache to get the full results Still, a good read! Cheers

Josh