Problem
A NAS loses one of two redundant network links because of switch configuration drift, leaving failover untested until the primary link fails.
Solution
Root Cause / Diagnostic:
Redundant Link Aggregation (LACP / 802.3ad) requires synchronized configuration across both the NAS network stack and managed switch ports. A switch reboot, VLAN reconfiguration, or firmware update can silently drop LACP trunking on the secondary link; the NAS continues operating on the primary link without warning until an unexpected link failure exposes the missing redundancy.
Actionable Fix:
1. LACP Trunking Audit & Configuration: In the managed switch CLI/GUI, re-verify that the port-channel group is active, set to 802.3ad LACP mode, and matches the NAS bonding configuration.
2. Automated Link Health Monitoring: Configure SNMP traps and NAS email alerts to notify administrators immediately when any bonded interface link state drops or changes speed.
3. Controlled Failover Pull-Test: While running a continuous ping and video playback test, physically disconnect the primary network cable to verify seamless, sub-second failover to the secondary link.
Pro Tip:
Redundancy that isn't tested is just wishful thinking; unplug your primary NAS network cable during a maintenance window to make sure your backup link actually takes over without dropping active edits.
Redundant Link Aggregation (LACP / 802.3ad) requires synchronized configuration across both the NAS network stack and managed switch ports. A switch reboot, VLAN reconfiguration, or firmware update can silently drop LACP trunking on the secondary link; the NAS continues operating on the primary link without warning until an unexpected link failure exposes the missing redundancy.
Actionable Fix:
1. LACP Trunking Audit & Configuration: In the managed switch CLI/GUI, re-verify that the port-channel group is active, set to 802.3ad LACP mode, and matches the NAS bonding configuration.
2. Automated Link Health Monitoring: Configure SNMP traps and NAS email alerts to notify administrators immediately when any bonded interface link state drops or changes speed.
3. Controlled Failover Pull-Test: While running a continuous ping and video playback test, physically disconnect the primary network cable to verify seamless, sub-second failover to the secondary link.
Pro Tip:
Redundancy that isn't tested is just wishful thinking; unplug your primary NAS network cable during a maintenance window to make sure your backup link actually takes over without dropping active edits.