Checkmk Werk 10494: lnx_if: Fixed confusion of interface state UNKNOWN, DOWN if ethtool output is missing

ID: 10494 Title: lnx_if: Fixed confusion of interface state UNKNOWN, DOWN if ethtool output is missing Component: Checks & agents Level: 1 Class: Bug fix Version: 1.7.0i1 If the command {{ethtool}} provides information about interfaces the operational state of an interfaces is UP if ethtool outputs {{Link detected: yes}} otherwise DOWN in case of {{Link detected: no}}. If this output is missing then the interface flags in angle brackets of the command {{ip}} are used to get the operational state. Out interpretation was as following: If the flags contain UP, the operational status of the interface is UP. If the flags contain DOWN, the status is DOWN otherwise it is UNKNOWN. But we wrongly assumed that these flags contain DOWN. This has been fixed and now it is handled as following: If the flags contain UP, the status is UP otherwise it is DOWN.