Network fail after new card

[tre4B]

Still moving towards getting my server working. Initially I got it running reliably with the onboard network port and once sata card in the PCIe running a disk.

I added a network PCIe card as I wanted more ports and though it booted it would not attach to the network. I tried a number of things but I could not get it to attach to the network. Eventually I installed proxmox again from the USB stick and it all worked perfectly.

Today I received the second Sata card which I installed, and again the networking stopped working. The server starts fine but the network refuses to connect. I removed the new card and it started and ran fine. Put it back in and it was again not on the network. Then I put the new card in where the old sata card was and everything started fine again proving the new card is fine.

I suspect if I once again install from the stick this will all work. This is fine while I am building the machine, however in the future when I have things installed on it this will be undesirable. Better I learn to understand what is happening and what I need to do about it by getting it to work with the three cards I have in it. Can anyone tell me what the issue is and what I should actually be doing?

 

[leesteken]

This is very common, but you would need to know it before you can find it in the forum: the network device names depend on the PCI ID of the network controller.
When you add or remove (or enable or disable) PCI(e) devices, the PCI ID of other devices (which have higher numbers) can change (typically by 1). Therefore the network device changes its name when you added a PCI(e) add-in card and the name no longer matches the configuration (and the network does not work).
Use ip a to determine the new network device name and adjust /etc/network/interfaces (for example using nano /etc/network/interfaces) accordingly (using the Proxmox host console with a physical keyboard and display).

 

[tre4B]

Thank you so much. That wax exactly the problem and all is working happily now