Cisco Switch Reboot Loops: A Widespread DNS Client Bug Impacting Network Operations in North East India

In a development that has raised concerns among network administrators worldwide, including those in North East India, multiple Cisco switch models have been hit by reboot loops due to a DNS client bug. This issue, first reported by BleepingComputer on January 8, 2026, has disrupted network operations across various sectors, causing severe inconvenience.

Impacted Cisco Switch Models

The bug appears to affect a wide range of Cisco switch models, including the CBS250 series, CBS350 series (including the CBS350-24P-4G), Cisco Catalyst C1200 series, SG350, SG350X, SG550X series, and potentially others. These switches form the backbone of many networks, and their sudden malfunction has caused significant disruption.

Global Impact and Timing

Reports suggest that the failures began around the same time across separate networks, indicating a global trigger or a time-based condition. This suggests that network administrators worldwide may be affected, including those in North East India who rely on Cisco switches for their network infrastructure.

Temporary Workarounds and Cisco Response

Administrators have discovered temporary workarounds to stop the reboot loops, such as disabling DNS resolution, disabling SNTP or time synchronization, and blocking outbound internet access from switch management interfaces. However, these are temporary solutions, and a long-term fix is eagerly awaited from Cisco.

Implications for North East India and Beyond

The widespread impact of this bug underscores the importance of robust network infrastructure and the need for regular updates and maintenance. In North East India, where digital transformation is underway, such incidents can potentially slow down the pace of progress. On a broader scale, such incidents highlight the vulnerabilities that exist in our increasingly interconnected world and the need for proactive measures to mitigate risks.

Looking Forward

As network infrastructure becomes increasingly critical to our daily lives and businesses, incidents like this serve as a reminder of the need for vigilance and preparedness. Cisco is yet to publicly disclose the root cause of the bug, and it is crucial that they address the issue promptly to prevent further disruptions. In the meantime, network administrators must stay vigilant and implement temporary workarounds to keep their networks running smoothly.