/etc/network

/etc/network 是 Debian 体系里“老一代网络配置”的地盘，主要给 ifupdown 用的，和 netplan / systemd-networkd 是不同年代、不同体系的东西。

Examples

# This file is generated from information provided by the datasource.  Changes
# to it will not persist across an instance reboot.  To disable cloud-init's
# network configuration capabilities, write a file
# /etc/cloud/cloud.cfg.d/99-disable-network-config.cfg with the following:
# network: {config: disabled}
auto lo
iface lo inet loopback

auto eth0
iface eth0 inet static
    address 192.168.123.3/28
    config_netfail off
    is_hotplugged off

auto eth1
iface eth1 inet static
    address 49.119.135.113/24
    config_netfail off
    is_hotplugged off
    post-up route add default gw 49.119.135.1 || true
    pre-down route del default gw 49.119.135.1 || true