Configuring a 40GB Ethernet connection between two computers
Configuring a 40GB Ethernet connection between two computers
I found 40gb dual port QSFP cards on eBay for $13. I wanted to test connecting them between my main PC and server box. Two cards and a cable cost $40 total—worth it? I ordered Sun Oracle OEM Connectx-3 cards, tested them on a bench, flashed the latest CX354a-FCBT firmware for 40gbE. I currently have one card on my PC and another on the bench to figure out setup before moving the server. Both cards are set to ETH, show 40gbE links, and display traffic status. Lights are on for both. However, I can’t get the two PCs to communicate or ping each other. I’ve tried autoconfig IPs and manual IPs, both running Windows 10. If you need more details, let me know. Thanks for your help.
You might need to configure the network for this instruction. It applies to Ethernet connections with a 40GbE setup, except the physical cable changes. As long as both devices have network access, proceed.
1. Open “Control Panel -> Network and Internet -> Network and Sharing Center -> Change Adapter Settings.”
2. Click “Change adapter settings” to view available options. Pick the LAN adapter for your connection, usually labeled as Ethernet with a network cable icon.
3. Right-click the adapter and choose “Properties.” This opens the connection details.
4. On the network tab, set the IP address and subnet mask for each computer:
- First PC: IP – 192.168.0.1, Subnet Mask – 255.255.255.0
- Second PC: IP – 192.168.0.2, Subnet Mask – 255.255.255.0
Make sure the IP addresses differ between machines.
5. Connect a crossover cable to the corresponding network ports on both devices. Note that many laptops lack a dedicated LAN port.
6. Right-click “This PC” → “Properties” → “Change settings -> Change.”
7. On the workgroup section, ensure both PCs share the same group name (default is WORKGROUP, but change as needed).
8. Go to the drive you wish to share, click “Advanced Sharing,” then “Advanced Sharing.”
9. Check the box for “Share this folder” and click “Apply -> OK.”
Now your two Windows computers are linked and can share files.
I found assistance elsewhere, but the problem stemmed from Windows Firewall. I configured the primary network connections as private and kept the firewall active for private networks. The direct link was marked public, and the firewall was turned off for public connections. Finally, I adjusted the jumbo frame MTU to achieve 10Gb/s over the connection.