Global DNS Crash Triggers Reboot Loops Across Cisco Small Business Switches

Global DNS Crash Triggers Reboot Loops Across Cisco Small Business Switches

A global DNS crash on January 8, 2026, caused Cisco Small Business Switches to reboot repeatedly due to a flaw in the DNS client process. The issue affected multiple models and firmware versions, with workarounds involving disabling DNS or SNTP curing network instability. #CiscoSwitches #DNSCrash

Keypoints

  • A DNS client flaw caused widespread reboot loops in Cisco Small Business Switches.
  • The problem surfaced around 2:00 AM and impacted devices globally across multiple models.
  • Fatal errors in the DNSC task led to core dumps and switch resets, triggered by DNS resolution failures.
  • Switches attempting to resolve specific domains like “www.cisco.com” or time synchronization servers were most affected.
  • Workarounds included disabling DNS and SNTP services until a fix or patch is released.

Read More: https://thecyberexpress.com/dns-crash-cisco-small-business-switches/