Ubuntuで固定IPを設定する

Setting a Static IP in Ubuntu – Linux IP Address Tutorial

DHCPで割り振られているIPの設定を確認する。

$ ifconfig eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 inet 192.168.2.238 netmask 255.255.255.0 broadcast 192.168.2.255 [...]

今回指定したいIPは、192.168.2.20で設定する。 192.168.2.1は（DHCPでIPを割り振っている）ルータのIPです。

$ cat /etc/netplan/99_config.yaml network: version: 2 renderer: networkd ethernets: eth0: dhcp4: false addresses: [192.168.2.20/24] gateway4: 192.168.2.1 nameservers: addresses: [8.8.8.8,8.8.8.4]

netplan tryで一見問題なく反映されているように見えますが、ifconfigでIPを確認しても変更されていません。

$ sudo netplan try Do you want to keep these settings? Press ENTER before the timeout to accept the new configuration Changes will revert in 114 seconds Configuration accepted.

netplan --debu applyを実行すると、WARNING:Falling back to a hard restart of systemd-networkd.serviceなるエラーが発生します。

$ sudo netplan --debu apply ** (generate:2077): DEBUG: 21:21:56.826: starting new processing pass ** (generate:2077): WARNING **: 21:21:56.827: `gateway4` has been deprecated, use default routes instead. See the 'Default routes' section of the documentation for more details. ** (generate:2077): DEBUG: 21:21:56.827: We have some netdefs, pass them through a final round of validation ** (generate:2077): DEBUG: 21:21:56.827: eth0: setting default backend to 1 ** (generate:2077): DEBUG: 21:21:56.827: Configuration is valid ** (generate:2077): DEBUG: 21:21:56.828: Generating output files.. ** (generate:2077): DEBUG: 21:21:56.829: openvswitch: definition eth0 is not for us (backend 1) ** (generate:2077): DEBUG: 21:21:56.829: NetworkManager: definition eth0 is not for us (backend 1) DEBUG:netplan generated networkd configuration changed, reloading networkd ** (process:2075): DEBUG: 21:21:57.120: starting new processing pass ** (process:2075): WARNING **: 21:21:57.121: `gateway4` has been deprecated, use default routes instead. See the 'Default routes' section of the documentation for more details. ** (process:2075): DEBUG: 21:21:57.121: We have some netdefs, pass them through a final round of validation ** (process:2075): DEBUG: 21:21:57.121: eth0: setting default backend to 1 ** (process:2075): DEBUG: 21:21:57.122: Configuration is valid DEBUG:Merged config: b'' DEBUG:no netplan generated NM configuration exists ** (process:2075): DEBUG: 21:21:57.138: starting new processing pass ** (process:2075): WARNING **: 21:21:57.138: `gateway4` has been deprecated, use default routes instead. See the 'Default routes' section of the documentation for more details. ** (process:2075): DEBUG: 21:21:57.138: We have some netdefs, pass them through a final round of validation ** (process:2075): DEBUG: 21:21:57.138: eth0: setting default backend to 1 ** (process:2075): DEBUG: 21:21:57.138: Configuration is valid DEBUG:Merged config: b'' DEBUG:Link changes: {} DEBUG:netplan triggering .link rules for lo DEBUG:netplan triggering .link rules for eth0 DEBUG:netplan triggering .link rules for eth1 ** (process:2075): DEBUG: 21:21:57.490: starting new processing pass ** (process:2075): WARNING **: 21:21:57.490: `gateway4` has been deprecated, use default routes instead. See the 'Default routes' section of the documentation for more details. ** (process:2075): DEBUG: 21:21:57.490: We have some netdefs, pass them through a final round of validation ** (process:2075): DEBUG: 21:21:57.491: eth0: setting default backend to 1 ** (process:2075): DEBUG: 21:21:57.491: Configuration is valid ** (process:2075): DEBUG: 21:21:57.491: starting new processing pass ** (process:2075): WARNING **: 21:21:57.491: `gateway4` has been deprecated, use default routes instead. See the 'Default routes' section of the documentation for more details. ** (process:2075): DEBUG: 21:21:57.492: We have some netdefs, pass them through a final round of validation ** (process:2075): DEBUG: 21:21:57.492: eth0: setting default backend to 1 ** (process:2075): DEBUG: 21:21:57.492: Configuration is valid DEBUG:Merged config: b'' WARNING: systemd-networkd is not running, output will be incomplete. Failed to reload network settings: No such file or directory WARNING:Falling back to a hard restart of systemd-networkd.service

Ubuntu Linux で LAN アダプターの MTU を設定する よりFalling back to a hard restart of systemd-networkd.serviceのエラーが出たら、applyをもう一度実行する（不思議なことに解決する）