What it means
Failover moves new traffic to a backup when monitoring detects a primary-link failure. Load balancing distributes eligible traffic according to the router's rules. Existing sessions can break when the public address changes. Two links sharing the same upstream infrastructure may fail together.
How this affects everyday use
Incorrect detection targets, mismatched routing rules, exhausted mobile data or a standby link that was never tested can undermine the backup. A working Ethernet port alone does not prove internet reachability.
A practical example
Fibre fails during a meeting; the router selects cellular, but the call reconnects because its address changed.
What to check
- Test each connection independently with the other disconnected.
- Inspect health checks and failback behaviour in the model's manual.
- Confirm backup data limits and which devices may use it.
Practical next steps
- Configure a supported failover policy.
- Simulate failure during an agreed maintenance window and record recovery.
- Restrict high-volume backups on metered service.
Keeping it reliable
Retest periodically and after provider changes. Allow for power failures and shared infrastructure. Do not promise uninterrupted calls or bonded bandwidth without a specifically supported solution.