I have Ubuntu server 20.04.3 installed on a server with two network cards, one of them used for the management interface (ilo) and the other one is the main one, the ip a output is as the following:
1: lo: <LOOPBACK> mtu 65536 qdisc noqueue state DOWN group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
2: eno1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
link/ether 27:fa:e7:31:df:d8 brd ff:ff:ff:ff:ff:ff
inet 10.1.1.23/24 brd 10.1.1.255 scope global eno1
valid_lft forever preferred_lft forever
inet6 fe80::3eae:a3dd:fee91:4fd8/64 scope link
valid_lft forever preferred_lft forever
3: eno2: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc mq state DOWN group default qlen 1000
link/ether 38:ae:e7:91:2d:f9 brd ff:ff:ff:ff:ff:ff
However, the interfaces file in /etc/network/interfaces is totally empty while the server is reachable and can access the internet. Any idea why this happening here?