# Configuring an Ethernet connection by using nmtui If you connect a host to an Ethernet network, you can manage the connection’s settings in a text-based user interface. Use the `nmtui` application to create new profiles and to update existing ones on a host without a graphical interface.
Note
In `nmtui`:
- Navigate by using the cursor keys. - Press a button by selecting it and hitting Enter. - Select and clear checkboxes by using Space. - To return to the previous screen, use ESC.
**Prerequisites**
- A physical or virtual Ethernet Network Interface Controller (NIC) exists in the server’s configuration.
**Procedure**
1. If you do not know the network device name you want to use in the connection, display the available devices:
```plaintext # nmcli device status DEVICE TYPE STATE CONNECTION enp1s0 ethernet unavailable -- ... ```
2. Start `nmtui`:
```plaintext # nmtui ```
3. Select **Edit a connection**, and press Enter. 4. Choose whether to add a new connection profile or to modify an existing one:
- To create a new profile:
1. Press **Add**. 2. Select **Ethernet** from the list of network types, and press Enter.
- To modify an existing profile, select the profile from the list, and press Enter.
5. Optional: Update the name of the connection profile. On hosts with multiple profiles, a meaningful name makes it easier to identify the purpose of a profile. 6. If you create a new connection profile, enter the network device name into the **Device** field. 7. Depending on your environment, configure the IP address settings in the `IPv4 configuration` and `IPv6 configuration` areas accordingly. For this, press the button next to these areas, and select:
- **Disabled**, if this connection does not require an IP address. - **Automatic**, if a DHCP server dynamically assigns an IP address to this NIC. - **Manual**, if the network requires static IP address settings. In this case, you must fill further fields:
1. Press **Show** next to the protocol you want to configure to display additional fields. 2. Press **Add** next to **Addresses**, and enter the IP address and the subnet mask in Classless Inter-Domain Routing (CIDR) format. If you do not specify a subnet mask, NetworkManager sets a `/32` subnet mask for IPv4 addresses and `/64` for IPv6 addresses. 3. Enter the address of the default gateway. 4. Press **Add** next to **DNS servers**, and enter the DNS server address. 5. Press **Add** next to **Search domains**, and enter the DNS search domain.
**Figure 2.1. Example of an Ethernet connection with static IP address settings**
[ ![Static IP address settings in `nmtui`](https://access.redhat.com/webassets/avalon/d/Red_Hat_Enterprise_Linux-10-Configuring_and_managing_networking-en-US/images/31ecc89b0c0aad7279a15f02132175ae/nmtui-ethernet-static-IP.png) ](https://access.redhat.com/webassets/avalon/d/Red_Hat_Enterprise_Linux-10-Configuring_and_managing_networking-en-US/images/31ecc89b0c0aad7279a15f02132175ae/nmtui-ethernet-static-IP.png "Static IP address settings in `nmtui`")
8. Press **OK** to create and automatically activate the new connection. 9. Press **Back** to return to the main menu. 10. Select **Quit**, and press Enter to close the `nmtui` application.
**Verification**
1. Display the IP settings of the NIC:
```plaintext # 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 ```
2. Display the IPv4 default gateway:
```plaintext # ip route show default default via 192.0.2.254 dev enp1s0 proto static metric 102 ```
3. Display the IPv6 default gateway:
```plaintext # ip -6 route show default default via 2001:db8:1::fffe dev enp1s0 proto static metric 102 pref medium ```
4. Display the DNS settings:
```plaintext # 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. 5. Use the `ping` utility to verify that this host can send packets to other hosts:
```plaintext # 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](https://access.redhat.com/solutions/3068421).