Avoid Network Loops

Redundant switch connections improve availability, but incorrect cabling can create a loop. Traffic then circulates continuously, overwhelms the network, and can trigger a broadcast storm.

How loops happen

Connecting two switches with multiple independent cables creates more than one active path. Without a LAG or a correctly functioning spanning tree, traffic may repeatedly travel through both switches.

How RSTP protects the network

RSTP detects redundant paths and blocks selected ports to prevent loops. A blocked port is not necessarily broken—it may be waiting to take over if the active path fails.

Use LAGs correctly

If multiple cables should act as one connection, assign them to the same LAG. Do not treat several independent cables between the same switches as free additional bandwidth.