Automatic failover is one of those things you swear you’ll set up “next week”… right up until the day your primary circuit drops and you discover your backup connection is basically decorative.
If you have an LTE/5G backup, a secondary ISP, or a redundant link at a site, this post will help you set up failover in a practical way—and verify it actually works before you need it.
These terms get tossed around like they’re interchangeable. They aren’t.
Both can be useful. But if your goal is business continuity, failover needs to be rock-solid even if you don’t load-balance at all.
If you’re using SD-WAN, failover and load balancing are often part of the design—along with app prioritization and performance monitoring. Fusion Connect’s Managed SD-WAN offering is built around multi-link resilience, so policies can be tuned to what matters most when a link degrades or drops.
Before you touch settings, check whether your edge device (router/firewall) supports:
If you’re not sure, look in your router/firewall interface for terms like:
If none of that exists… you may have a backup link, but not a backup strategy.
A common mistake is using a health check that only verifies your ISP gateway is reachable. That can pass even when the internet is effectively down.
Better practice: configure probes to multiple reliable destinations, such as:
Why multiple? Because one target can fail without your whole connection being dead.
General starting point settings:
This helps reduce “flapping” (bouncing between links) while still failing over quickly.
If you don’t want link monitoring to be a “hope for the best” situation, this is where ongoing visibility helps. Fusion Connect’s Managed Network Services are positioned around proactive monitoring and support—useful when you want failover behavior validated and watched over time, not only during emergencies.
In most SMB environments, the simplest approach is: everything fails over.
But there are times you may want rules, for example:
If you have LTE as your backup, it’s smart to define:
This helps prevent your backup link from getting crushed by non-essential traffic.
If you’re standardizing backup connectivity across many locations, Fusion Connect’s Wireless Broadband positioning (LTE/4G/5G, including multi-carrier eSIM options) is designed for situations where you need a consistent approach to cellular backup rather than a one-off hotspot solution.
If you are load balancing, verify it’s behaving the way you think.
Quick checks:
What you’re looking for is consistency, not chaos. If traffic distribution is wildly uneven, it may be configured for failover—not balancing—or your rules are steering more than you intended.
Most routers/firewalls will log WAN events. Look for entries related to:
If your device supports event notifications, enable alerts for WAN state changes. Automatic failover is great—but only if you know it happened.
Testing failover doesn’t need to be dramatic, but it does need to be real.
Safe test method (recommended):
What to document:
If you’re building your failover plan from scratch—or trying to sanity-check what “good” looks like—Fusion Connect also has a practical overview of backup internet options and how failover typically works in real environments.
Failover problems tend to show up as:
Common causes include:
If you see these symptoms, it’s time to escalate—because “mostly works” is not the goal when you’re talking about business continuity.
In some locations, cellular is weak, inconsistent, or constrained by building materials and geography. If you need a physically diverse backup path, satellite internet can be an option.
Fusion Connect positions Starlink Satellite Internet as an alternative or backup connectivity path for businesses that need coverage where other options fall short.
A backup connection is only valuable if:
Because “we have LTE backup” sounds great… until the day you discover you don’t.