This article explains the meaning and impact of the syslog message " dcd_config_read_interfaces_ether_802_3ad:Unable to get ifd " on MX Series routers.

A log message similar to the following is observed following a configuration change on the interfaces: 

dcd[15696]: dcd_config_read_interfaces_ether_802_3ad:Unable to get ifd(et-4/0/7) speed from pic hwdb

Whenever there is a configuration change on the interfaces, the device control daemon (DCD) tries to get the interface speed from the PIC hardware database (which is maintained by chassisd). If it is unable to get a response from the hardware database, it configures the default speed for the port, depending on the port type (for "et" interfaces, it is 40G) and prints the above log message.

15696 is the process ID for DCD.

This log message does not have any impact and can therefore be safely ignored.