In distributed systems, link and site failure is detected by —

In distributed systems, to detect link failure or site failure , the common technique is handshaking (exchange of signals to check if the other node is alive). Token passing is for access control, not failure detection. Polling is used but not primarily for failure detection across all nodes. Important Points (English) In a distributed system , detecting link failure or site (node) failure is critical.

Handshaking is the most common technique used for this purpose.

In handshaking, nodes periodically exchange signals/messages (heartbeats).

If a node does not receive a response within a fixed time, the other node is assumed to have failed .

Handshaking helps in detecting both communication link failures and node crashes .

Token passing is mainly used for mutual exclusion and access control , not for failure detection.

Polling can be used in some cases, but it is not the standard or primary technique for failure detection in distributed systems.

Handshaking is widely used due to its simplicity and reliability .

Correct Technique: ✅ Handshaking