What is contained in the trailer of a data-link frame?physical addresserror detectionlogical addressdata

The trailer of a data-link frame contains specific information used for managing data transmission over a network. The key components included in the trailer are:

1. Error Detection: The trailer typically includes a frame check sequence (FCS) that helps in detecting errors that may have occurred during transmission. This sequence often uses cyclic redundancy check (CRC) techniques to ensure data integrity.

2. Physical Address: Although it's more common to find the physical address in the header, certain protocols may repeat the destination or source physical addresses in the trailer for additional reference.

3. Other Control Information: The trailer may also contain other control information or padding bits to ensure that the frame meets a minimum length requirement.

Notably, logical addresses are generally not included in the data-link frame trailer, as they pertain to higher layers in the network stack, specifically the network layer.

In summary, the trailer generally contains Error Detection information, with some cases of Physical Addressing, but does not include logical addressing.