Network-scripts deprecation in Rocky Linux 9 affecting ifcfg persistence

The direct answer

On Rocky Linux 9, legacy ifcfg files in /etc/sysconfig/network-scripts/ are not read at all by default. The network-scripts package and the initscripts-based network service were removed in the EL9 generation, and NetworkManager ships configured to use only the keyfile plugin. Profiles live as .nmconnection files in /etc/NetworkManager/system-connections/. So the documented behavior is: an ifcfg file with no corresponding NetworkManager profile is inert — nothing creates a connection from it, at boot or otherwise.

And no, nmcli connection reload does not synchronize legacy script parameters into runtime state. It only re-reads on-disk profiles from plugins that are actually loaded. With a keyfile-only configuration there is nothing to read in /etc/sysconfig/network-scripts/, so the reload is a no-op for your ifcfg files.

Confirmed facts vs. the likely explanation

Confirmed: Rocky 9 has no network-scripts package, no ifup/ifdown via initscripts, and NetworkManager is the sole supported configuration path. Likely explanation for your symptom: the system was either freshly installed (ifcfg files were never imported) or upgraded from Rocky 8, leaving ifcfg files on disk that the keyfile-only NetworkManager ignores. You can confirm which plugin set is active with:

NetworkManager --print-config | grep -A2 '\[main\]'

If the plugins line shows only keyfile (the default), ifcfg files are definitively not being consumed.

Migrating the existing ifcfg files

Convert each legacy file into a native keyfile profile rather than trying to keep the old format alive:

nmcli connection import type ifcfg file /etc/sysconfig/network-scripts/ifcfg-eth0
nmcli connection show
nmcli connection up <profile-name>

The import writes a .nmconnection file under /etc/NetworkManager/system-connections/. Verify persistence with a reboot or nmcli connection down/up cycle, and confirm the profile appears in nmcli -f NAME,UUID,TYPE,DEVICE connection show.

Caveats that change the recommendation

• Permissions: keyfiles must be owned by root with mode 600; NetworkManager silently refuses to load world-readable profiles.
• Cloud images: if this is a cloud instance, cloud-init may regenerate network config on reboot and overwrite manual changes — check /etc/cloud/cloud.cfg.d/ before assuming your edits persist.
• Do not reinstall network-scripts from EL8 repositories; it is unsupported on EL9 and conflicts with NetworkManager.
• Going forward, manage interfaces with nmcli, nmtui, or nmstate. Hand-editing keyfiles is fine, but requires nmcli connection reload followed by re-activating the profile — reload alone does not apply changes to a live interface.

One detail worth checking if the import behaves unexpectedly: whether the ifcfg file uses directives with no keyfile equivalent (some legacy scripting hooks like ifup-local don't translate). If nmcli connection import reports dropped keys, share that output and the original file's non-standard lines before assuming the migration is complete.