Member Avatar for Davepl

We have one computer with 2 NICs. The first NIC connects to a DSL modem. Second NIC to a wireless router, (used to connect to card readers). Each has a different IP address, on different subnets. When the wireless router is on, it blocks internet access, from the DSL line.
As soon as we turn off the router, internet access comes back on.
So the browser must be looking to the router by default for internet access. We would like it to look first at the DSL modem. Wondering if anyone has had success configuring internet access with 2 NICs?

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— the symptom is the machine choosing the wrong "default route." The operating system forwards any destination it doesn't know about to whatever interface has a 0.0.0.0/0 route (the default gateway). In practice the cleanest fixes are (A) stop the wireless box from advertising itself as a default gateway (put it in AP/bridge mode or disable its DHCP), or (B) give the router-linked NIC a static IP with no gateway and keep the DSL NIC as the only interface with a default gateway. That keeps Internet traffic on the DSL link while still allowing the card-reader subnet to be reached on the other NIC.

Practical Windows steps to try (replace addresses/subnets with the actual values on the network):

  • Verify current routes and adapter info:
    ipconfig /all
route print
  • If the router is on 192.168.2.0/24 and the router IP is 192.168.2.1, add a persistent route so traffic to the card-reader net goes over the router NIC while everything else uses DSL:
    route add 192.168.2.0 mask 255.255.255.0 192.168.2.1 -p
  • Alternatively (safer): on the router-facing NIC set a static IP and leave the Default Gateway field blank (or disable DHCP on the router). That prevents the router from becoming the machine's default Internet gateway.

If removing both gateways isn’t possible, change the interface metrics so the DSL NIC is preferred: open IPv4 → Advanced on each adapter, uncheck “Automatic metric” and set a lower metric on the DSL NIC (lower = higher priority).

For : using two ADSL links to increase throughput for the whole LAN requires a dual-WAN/load‑balancing router or a specialized bonding service — a plain Windows PC won’t transparently aggregate two consumer DSL connections. Also avoid plugging two DHCP servers into the same switch without isolation; they will conflict. Quick troubleshooting checklist: confirm adapter IPs, run route print, use tracert to see the first hop to the Internet, and ping both gateways to verify reachability.

Member Avatar for Andrew Wiggin

Unless you are trying to insulate the rest of your network from the internet, you could just run the net into the router and get your internet through it.

If that isn't an option for whatever reason, double check that your router isn't sending itself as the default gateway in its DHCP duties. Also, make sure your DSL is the default gateway on its NIC.

Member Avatar for ajayvats

We have one computer with 2 NICs. The first NIC connects to a DSL modem. Second NIC to a wireless router, (used to connect to card readers). Each has a different IP address, on different subnets. When the wireless router is on, it blocks internet access, from the DSL line.
As soon as we turn off the router, internet access comes back on.
So the browser must be looking to the router by default for internet access. We would like it to look first at the DSL modem. Wondering if anyone has had success configuring internet access with 2 NICs?

hello everyone....

i am having similar problem with my network.... pls see and help if it can be solved.....

Hello DMR,

I am having a problem.....

First, I have a lan with 32 port switch (Dlink). 5 system have two nics : one wired (rtl8139), other wireless netgear wg311v3.

Secondly i have two internet broadband connections, both with adsl modem with inbuilt wireless accesspoint along with four ethernet ports in each modem.

i have connected both adsl modem to my 32port switch.

Generally i am able to use whatever internet connection and file/printer sharing at any of the pc's in my lan.

I want to use both internet connection at those two nic pc's along with file and printer sharing.


The First problem is , when i use any of the pc with 2nic's enabled and connected (i.e wired nic with switch and wireless nic with wireless accesspoint of any one modem), the lan is not accessible at any of the pc in the lan. How do i get it to work.

Secondly, how can i use both internet connection at a single pc along with file and printer sharing, with internet connection working simultaneously to speed up any downloads/uploads etc.

my name is ajay sharma

daniweb id: ajayvats

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