Okay, I think you found it. This means that the card is installed and recognized:
enp2s0: flags=4098<BROADCAST,MULTICAST> mtu 1500
ether 14:fe:b5:df:5a:0c txqueuelen 1000 (Ethernet)
RX packets 0 bytes 0 (0.0B)
RX error - dropped 0 overruns 0 frame 0
TX packets 0 bytes 0 (0.0B)
TX errors 0 dropped 0 overruns 0 carrier 0 ...
I had a similar issue (interfaces do not reconnect after restarting networking), and found the answer here (on Server Fault). I had to change allow-hotplug to auto. I have no idea why it works.
This answer from the Unix & Linux also explicitly mentions having to manually enable the interface if using allow-hotplug instead of auto.
I'm on Debian 10 (...
Start by verifying that the Ethernet controller does appear in the output of lspci:
02:00.0 Ethernet controller: Broadcom Inc. and subsidiaries NetXtreme BCM5722 Gigabit Ethernet PCI Express
"lspci -n" will also report the PCI IDs of the device, which could be of use in later checks:
02:00.0 0200: 14e4:165a
By Googling you will find what driver ...
Here's the unexpected part. I can ping the IP address of the 10Gb/s from my laptop on the production network (see below).
That's not unexpected: Both IP addresses are in the same subnet, so any ARP request for 192.168.69.224 in "production network" behind enp1s0f1 will get broadcast to this address, and the Linux kernel will answer this for any ...
Linux kernel describes every Ethernet adapter(physical device or virtual) by struct net_device (struct net_device). Every struct net_device has a set of struct net_device_ops which should be implemented by device driver. The most important of them:
ndo_open(). Called when you set Ethernet adapter to ON (ip link set up dev <eth_dev>).
The ethernet interface name enp6s0 means the PCI bus location (as indicated by e.g. the lspci command) of that NIC is 06:00.0.
If you don't have a network card at PCI bus location 01:00.0, you won't get interface name enp1s0. On many desktop motherboards, the PCI bus location 01:00.0 refers to the first long (16x) PCIe slot, which is the recommended ...
The naming convention for ethernet interfaces has been changed in some recent distributions of Linux. The interface names are now decided dynamically based on it's drivers.
For an in-depth explanation, see this article.
CMD which help to narrow it down to missing driver
sudo lshw -class network
I compared my HW ID 8086:15fa here and according to this https://cateee.net/lkddb/web-lkddb/E1000E.html included in Kernel 5.5–5.11, 5.12-rc+HEAD (so my 5.4 is just one version to old)
here few cmd to check
sudo lshw -class network