Said It Here

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 people tried

Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.

  1. 1
    Switching to a backup ISP
  2. 2
    Using multiple circuits or hoping communication gets restored quickly by splicers

In their words

Unedited, grouped by where they were said, most upvoted first within each place, each linked to the thread it came from.

r/sysadmin4 people · September 2026

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 ↗

MentalRip1893 · r/sysadmin · 17 upvotes

I got a flight tomorrow AM from LGA, pouring one out for the splicers and hoping for the bestsource ↗

WeirdKindofStrange · r/sysadmin · 1 upvotes

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 ↗

JimTheJerseyGuy · r/sysadmin · 1 upvotes

How in the world does a TRACON facility not have redundant communications?source ↗

Qel_Hoth · r/sysadmin · 1 upvotes

Where this came up

People with this problem also raised