Ubuntu 21.10 static ip network configuration

I have edited /etc/netplan/01-network-manager-all.yaml to get a static ip address:

network: version: 2 renderer: networkd ethernets: wlp0s20f3: dhcp4: no addresses: - 10.1.10.23/24 routes: - to: default via: 10.1.10.1 nameservers: addresses: [10.1.1.10]

After netplan apply everything is fine, the interface is configured according to the config, but after reboot, the interface gets some additional automatic dhcp configuration:

2: wlp0s20f3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000 link/ether cc:15:31:5e:bf:41 brd ff:ff:ff:ff:ff:ff inet 10.1.10.101/24 brd 10.1.10.255 scope global dynamic noprefixroute wlp0s20f3 valid_lft 5652sec preferred_lft 5652sec inet 10.1.10.23/24 brd 10.1.10.255 scope global secondary noprefixroute wlp0s20f3 valid_lft forever preferred_lft forever inet6 fe80::d6f7:2c10:8bf1:af66/64 scope link noprefixroute valid_lft forever preferred_lft forever

It is even somehow assigned an ipv6 address despite

net.ipv6.conf.all.disable_ipv6=1

being set in /etc/sysctl.conf

It seems like some service is changing the configuration, it didn't happen on 20.04.

How to disable this automatic configuration?

1 Answer

The DHCP address is provided by Network Manager. In order to use a scipt and therefore netplan, disable NM like this: How do I disable network manager permanently?

Next, your netplan file fails to provide the SSID and WPA2 password. I suggest that you amend it:

network: version: 2 renderer: networkd wifis: wlp0s20f3: dhcp4: no dhcp6: no addresses: [10.1.10.23/24] nameservers: addresses: [10.1.1.10] access-points: "network_ssid_name": password: "**********" routes: - to: default via: 10.1.10.1

Note that the SSID and password are enclosed in quotation marks ". Netplan is very specific about indentation, spacing, etc., so proofread carefully twice. Follow with:

sudo netplan generate
sudo netplan apply

Please note that in a deployment of several laptops in a network, wlp0s20f3 is very unlikely to be the same interface name for all. As @heynnema points out above, you will need to interrogate each laptop for its logical interface name.