Configuring an Ethernet connection by using nmcli 2.1. Configuring an Ethernet connection by using nmcli Copy link If you connect a host to the network over Ethernet, you can manage the connection’s settings on the command line by using the nmcli utility. Prerequisites A physical or virtual Ethernet Network Interface Controller (NIC) exists in the server’s configuration. Procedure List the NetworkManager connection profiles: # nmcli connection show NAME UUID TYPE DEVICE Wired connection 1 a5eb6490-cc20-3668-81f8-0314a27f3f75 ethernet enp1s0 By default, NetworkManager creates a profile for each NIC in the host. If you plan to connect this NIC only to a specific network, adapt the automatically-created profile. If you plan to connect this NIC to networks with different settings, create individual profiles for each network. If you want to create an additional connection profile, enter: # nmcli connection add con-name ifname type ethernet Skip this step to modify an existing profile. Optional: Rename the connection profile: # nmcli connection modify "Wired connection 1" connection.id "Internal-LAN" On hosts with multiple profiles, a meaningful name makes it easier to identify the purpose of a profile. Display the current settings of the connection profile: # nmcli connection show Internal-LAN ... connection.interface-name: enp1s0 connection.autoconnect: yes ipv4.method: auto ipv6.method: auto ... Configure the IPv4 settings: To use DHCP, enter: # nmcli connection modify Internal-LAN ipv4.method auto Skip this step if ipv4.method is already set to auto (default). To set a static IPv4 address, network mask, default gateway, DNS servers, and search domain, enter: # nmcli connection modify Internal-LAN ipv4.method manual ipv4.addresses 192.0.2.1/24 ipv4.gateway 192.0.2.254 ipv4.dns 192.0.2.200 ipv4.dns-search example.com Configure the IPv6 settings: To use stateless address autoconfiguration (SLAAC), enter: # nmcli connection modify Internal-LAN ipv6.method auto Skip this step if ipv6.method is already set to auto (default). To set a static IPv6 address, network mask, default gateway, DNS servers, and search domain, enter: # nmcli connection modify Internal-LAN ipv6.method manual ipv6.addresses 2001:db8:1::fffe/64 ipv6.gateway 2001:db8:1::fffe ipv6.dns 2001:db8:1::ffbb ipv6.dns-search example.com To customize other settings in the profile, use the following command: # nmcli connection modify Enclose values with spaces or semicolons in quotes. For details about which settings you can modify, see the nm-settings(5) man page on your system. Activate the profile: # nmcli connection up Internal-LAN Verification Display the IP settings of the NIC: # ip address show enp1s0 2: enp1s0: mtu 1500 qdisc fq_codel state UP group default qlen 1000 link/ether 52:54:00:17:b8:b6 brd ff:ff:ff:ff:ff:ff inet 192.0.2.1/24 brd 192.0.2.255 scope global noprefixroute enp1s0 valid_lft forever preferred_lft forever inet6 2001:db8:1::fffe/64 scope global noprefixroute valid_lft forever preferred_lft forever Display the IPv4 default gateway: # ip route show default default via 192.0.2.254 dev enp1s0 proto static metric 102 Display the IPv6 default gateway: # ip -6 route show default default via 2001:db8:1::fffe dev enp1s0 proto static metric 102 pref medium Display the DNS settings: # cat /etc/resolv.conf search example.com nameserver 192.0.2.200 nameserver 2001:db8:1::ffbb If multiple connection profiles are active at the same time, the order of nameserver entries depend on the DNS priority values in these profiles and the connection types. Use the ping utility to verify that this host can send packets to other hosts: # ping Troubleshooting Verify that the network cable is plugged-in to the host and a switch. Check whether the link failure exists only on this host or also on other hosts connected to the same switch. Verify that the network cable and the network interface are working as expected. Perform hardware diagnosis steps and replace defective cables and network interface cards. If the configuration on the disk does not match the configuration on the device, starting or restarting NetworkManager creates an in-memory connection that reflects the configuration of the device. For further details and how to avoid this problem, see the Red Hat Knowledgebase solution NetworkManager duplicates a connection after restart of NetworkManager service .