Two Network Cards

Networking/Security Forums -> Networking

Author: javlonchik PostPosted: Fri Dec 10, 2010 7:28 pm    Post subject: Two Network Cards
    ----
Hi everyone,

I am a newbie in the networking world and a little help would be appreciated in correctly configuring two NICs. I have searched your forum for multiple network card configurations, but none of them worked.

We have one PC (Win XP SP 2) - with network cards. One (native) uses the same network with other computers on the same floor and for Internet, and the other one is for using a special software upstairs on a different network. So two independent networks

Here is where the problem arises. Both of the NICs have static IPs.
Native NIC for flr 1
192.1.168.195
255.255.255.0
192.1.168.1

However, Internet stops working after one or two days. I constantly have to change the IP to 192.1.168.196 so on. And even that one expires in the next day. Any IP I put lasts for a day only.

What could be the cause? Automatic DNS and IP is not solving the issue.
Thanks!

PS. Forgot to mention. There is another computer on flr 1 with Win 7 that houses 2 NICs. But it never has the same problem.... I am getting a white hair over this already...

Author: PhiBerLocation: Your MBR PostPosted: Sat Dec 11, 2010 2:49 am    Post subject:
    ----
When the computer loses Internet connectivity, please do the following so that we can assist in troubleshooting - open up a command prompt and type 'route print' (without quotes). Copy and paste all of the information so that we can analyze.

Thanks!

Author: javlonchik PostPosted: Mon Dec 13, 2010 6:43 pm    Post subject:
    ----
PhiBer,

Thank you for your response. Because of the weekend, I didn't have any access to the troublemaker until today. Below is the route print log. Ran it when the Internet stopped working.

Code:
===========================================================================
Interface List
0x1 ........................... MS TCP Loopback interface
0x2 ...00 04 75 7a d6 f2 ...... 3Com EtherLink XL 10/100 PCI For Complete PC Man
agement NIC (3C905C-TX) - Packet Scheduler Miniport
0x3 ...00 1a a0 c0 9e 4f ...... Broadcom NetXtreme 57xx Gigabit Controller - Pac
ket Scheduler Miniport
===========================================================================
===========================================================================
Active Routes:
Network Destination        Netmask          Gateway       Interface  Metric
          0.0.0.0          0.0.0.0      192.168.1.1   192.168.1.195       1
          0.0.0.0          0.0.0.0    192.168.106.1  192.168.106.100      20
        127.0.0.0        255.0.0.0        127.0.0.1       127.0.0.1       1
      169.254.0.0      255.255.0.0  192.168.106.100  192.168.106.100      20
      192.168.1.0    255.255.255.0    192.168.1.195   192.168.1.195       20
    192.168.1.195  255.255.255.255        127.0.0.1       127.0.0.1       20
    192.168.1.255  255.255.255.255    192.168.1.195   192.168.1.195       20
    192.168.106.0    255.255.255.0  192.168.106.100  192.168.106.100      20
  192.168.106.100  255.255.255.255        127.0.0.1       127.0.0.1       20
  192.168.106.255  255.255.255.255  192.168.106.100  192.168.106.100      20
        224.0.0.0        240.0.0.0    192.168.1.195   192.168.1.195       20
        224.0.0.0        240.0.0.0  192.168.106.100  192.168.106.100      20
  255.255.255.255  255.255.255.255    192.168.1.195   192.168.1.195       1
  255.255.255.255  255.255.255.255  192.168.106.100  192.168.106.100      1
Default Gateway:     192.168.106.1
===========================================================================
Persistent Routes:
  None


Any diagnosis?

Author: PhiBerLocation: Your MBR PostPosted: Tue Dec 14, 2010 2:38 am    Post subject:
    ----
So is 192.168.106.100 your 2nd NIC? If so, please confirm the gateway that the 2nd NIC is supposed to go through.

Moreover, please post a route print when Internet connectivity is working for further analysis. Lastly, please confirm that 192.168.1.1 is your gateway/router to the Internet. Thanks!

Author: javlonchik PostPosted: Tue Dec 14, 2010 5:45 pm    Post subject:
    ----
Here is the route print IS working. Seems the same to me. Though we had to change the IP by one count.

Code:
===========================================================================
Interface List
0x1 ........................... MS TCP Loopback interface
0x2 ...00 04 75 7a d6 f2 ...... 3Com EtherLink XL 10/100 PCI For Complete PC Man
agement NIC (3C905C-TX) - Packet Scheduler Miniport
0x3 ...00 1a a0 c0 9e 4f ...... Broadcom NetXtreme 57xx Gigabit Controller - Pac
ket Scheduler Miniport
===========================================================================
===========================================================================
Active Routes:
Network Destination        Netmask          Gateway       Interface  Metric
          0.0.0.0          0.0.0.0      192.168.1.1   192.168.1.195       1
          0.0.0.0          0.0.0.0    192.168.106.1  192.168.106.100      20
        127.0.0.0        255.0.0.0        127.0.0.1       127.0.0.1       1
      169.254.0.0      255.255.0.0  192.168.106.100  192.168.106.100      20
      192.168.1.0    255.255.255.0    192.168.1.195   192.168.1.195       20
    192.168.1.195  255.255.255.255        127.0.0.1       127.0.0.1       20
    192.168.1.255  255.255.255.255    192.168.1.195   192.168.1.195       20
    192.168.106.0    255.255.255.0  192.168.106.100  192.168.106.100      20
  192.168.106.100  255.255.255.255        127.0.0.1       127.0.0.1       20
  192.168.106.255  255.255.255.255  192.168.106.100  192.168.106.100      20
        224.0.0.0        240.0.0.0    192.168.1.195   192.168.1.195       20
        224.0.0.0        240.0.0.0  192.168.106.100  192.168.106.100      20
  255.255.255.255  255.255.255.255    192.168.1.195   192.168.1.195       1
  255.255.255.255  255.255.255.255  192.168.106.100  192.168.106.100      1
Default Gateway:     192.168.106.1
===========================================================================
Persistent Routes:
  None


And the default gateway for NIC 2 is 192.168.106.1

Why is that Internet stops working?

Author: javlonchik PostPosted: Tue Dec 14, 2010 5:58 pm    Post subject:
    ----
192.168.1.1 is the default gateway for internet. At least to my knowledge.

Author: PhiBerLocation: Your MBR PostPosted: Tue Dec 14, 2010 6:45 pm    Post subject:
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Here is what I would recommend:
1. Download/install the latest updates/drivers on your network cards
2. Ensure that Windows 7 is fully patched with the latest patches
3. Set the 2nd NIC to have a metric of 25 instead of 20 and make it a persistent route. From an elevated command prompt, do the following:
Code:

route -p add [destination] [mask <netmask>] [gateway] [metric <metric>] [if <interface>].


Lastly, please confirm the IP, SM, DNS, and Gateway settings of your 2nd NIC and let us know if the above resolves the issue.

Author: javlonchik PostPosted: Tue Dec 14, 2010 6:55 pm    Post subject:
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Should I still perform these actions even though that computer has Win XP SP2 not Win 7?

Author: PhiBerLocation: Your MBR PostPosted: Tue Dec 14, 2010 7:07 pm    Post subject:
    ----
Yes please do so.

Author: javlonchik PostPosted: Wed Dec 15, 2010 11:47 pm    Post subject:
    ----
I updated the drivers and Win XP to SP 3. Internet went down every five minutes first. Very random. Now it is lasting more 15 mins or longer. Hopefully will last longer.

I tried to change the metric with the commands you provided. But getting the following error.

Code:
 route -p add 192.168.106.100  mask 255.255.25
5.0 192.168.106.1 metric 25
The route addition failed: The specified mask parameter is invalid. (Destination
 & Mask) != Destination.


???

Author: capiLocation: Portugal PostPosted: Thu Dec 16, 2010 1:07 am    Post subject:
    ----
There could be an IP conflict if the other computers on the 192.168.1.x network are obtaining their IPs automatically and you haven't reserved 195 on your DHCP server.

Please give us a schematic of your network. Something like:
Code:
  modem
      |
  home_router
   |      |       |
 PC1   PC2  problem_PC
                   |
                switch
                   |
                upstairs_PC

Author: PhiBerLocation: Your MBR PostPosted: Thu Dec 16, 2010 6:29 pm    Post subject:
    ----
Capi may also be correct in that another computer is stealing your IP address.

In regards to your route, please format it as such (the destination needs to be 192.168.106.0 and not the actual IP address). There is a slight possibility that since both metrics are 20, that the Internet is reverting to the 192.168.106.x IP. Can you confirm that the 192.168.106.x subnet does not have access to the Internet? If it does, the route add issue may not help.

Code:
route -p add 192.168.106.0  mask 255.255.255.0 192.168.106.1 metric 25

Author: javlonchik PostPosted: Thu Dec 16, 2010 7:21 pm    Post subject:
    ----
When it has an ip conflict Win XP usually displays a bubble message at the bottom.
Since the route -p add proved problematic, I changed it through TCP/Confgi advanced options and put the metric to 25 for the second NIC (192.168.106.1). I am sure it is not using the second NIC to connect to the Internet.

How do I reserve an IP through DNS so that other computers do not steal the ip (if that's the case)?

Author: PhiBerLocation: Your MBR PostPosted: Thu Dec 16, 2010 7:48 pm    Post subject:
    ----
Go into DHCP on your DHCP server and make a reservation...what server/network device acts as your DHCP server?



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