5.112 KCCFailedLinks
KCCFailedLinks is an abstract type that consists of a sequence of tuples, one tuple for each neighboring DC for which a connection attempt failed.
The fields of the tuple are the same as the fields of the KCCFailedConnections tuple.
The global variable dc for a DC has an associated field dc.kccFailedLinks, which maintains the DC's KCCFailedLinks state.