I know that Loop guard is STP (L2) and UDLD is different (L1).
I would like to know if implementing Loop Guard would serve the purpose without implementing UDLD ?
regarding Loop guard, I am not sure if it is necessary. I believe in STP by default , if a port does not receive BPDUs ,STP will do its calculation and eventually will have one of the redundant link in blocking mode. So why configure Loop Guard ?