Why didn't our backup internet fail over?
Backup internet failovers often fail during an outage because both the primary and secondary connections are routed through the same physical cable or suffer simultaneous outages. This leaves offices unexpectedly disconnected until staff can troubleshoot upstream peer failures and switch to a truly independent backup provider.
What the numbers show
Counted from the threads quoted below. How we count
- The most recent one is from October 2026.
- This comes up 91.9× more often in r/msp than across the site as a whole.
What people tried
Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.
Found another way around this?
Share your steps and trade-offs so fellow engineers don't have to reinvent the wheel. No account required.
Why didn't our backup internet fail over?
- 1Switching to a backup ISPDid this help you?
- 2Using multiple circuits or hoping communication gets restored quickly by splicersDid this help you?
- 3Stop the two 'DNS AGENT' services on the affected machineDid this help you?
- 4Buying a Starlink kit from a retail store like Costco or Home Depot for quick setupDid this help you?
- 5Using 5G business internet routers from providers like Verizon or AT&TDid this help you?
- 6Relying on mobile hotspot connections via personal cell phones temporarilyDid this help you?
In their words
Unedited, grouped by where they were said, most upvoted first within each place, each linked to the thread it came from.
“This morning I got a call that internet was down at one of our offices. Our ISP peers with Zayo, and traceroute fails after the Zayo hop in Seattle. Switching to our backup ISP who doesn't peer with Zayo, everything's running fine.”source ↗
“I got a flight tomorrow AM from LGA, pouring one out for the splicers and hoping for the best”source ↗
“Yeah, I saw they're saying the primary died and they only found out the backup was down when it didn't fail over. So, either you had two simultaneous failures or your primary and backup were routed through the same cable.”source ↗
“How in the world does a TRACON facility not have redundant communications?”source ↗
“Just had an influx of customer calls to helpdesk all seem to point to a DNS Filter issue.”source ↗
“AT&T showed up for a fiber install today only to say that they hit a snag and it will be 30 days or more.”source ↗
“We are looking at piviting. I think Starlink would work. We just have 20 people connecting cell phones to wifi for a task tracking app. Can anyone tell me about how long it was from ordering until equipment arrives?”source ↗
“Getting a lot of DNS probe errors”source ↗
“the one client on roaming clients just started throwing auth errors”source ↗
Where this came up
People with this problem also raised
- 76HubSpot is down and timing out right now
- 4Why is losing power so disorienting?
- 5Why are websites and APIs suddenly unreachable?
- 36Why are clients suddenly ghosting contracts and sales slowing down?
- 7Locked out of cloud service partner center after deauthorization
- 4Why does school admin never show up during a student crisis?