zxr10PortGroupSwitchStrategy reports the switching strategy used by this protection group, and per its description, a port protection group can only be configured with APS, Automatic Protection Switching. An admin reading aps(2) here confirms the group relies on the standard APS mechanism to detect a fault and automatically move traffic to the backup port without manual intervention. For example, seeing aps(2) tells an admin that a fiber cut on the working port should trigger an automatic switch to the backup port covered by zxr10PortGroupBackupPort, without needing a manual command.