TeraSwitch experienced a major incident on July 29, 2026 affecting Intra-Market Connectivity and Internet Exchanges and Peering, lasting 19d 22h. The incident has been resolved; the full update timeline is below.
Affected components
Update timeline
- investigating Jul 29, 2026, 07:15 PM UTC
Teraswitch is looking into general Internet Instability.
- identified Jul 29, 2026, 07:35 PM UTC
Teraswitch is currently working on mitigations related to this issue, although traffic issues have settled. At this time, it appears a bulk of the high-capacity US to EU cables had a fault around the same time. Our NY to London path, which had been cut and resolved earlier today, went down again, and our Ashburn to Frankfurt path suffered an outage around the same time. At this time, the network has stabilized and we are working to ensure any additional events are not as impactful to traffic.
- monitoring Jul 31, 2026, 02:33 PM UTC
Since the initial impact, Teraswitch’s Network Engineering team has identified the instability as a routing software failure triggered during a routine configuration change. We have removed the triggering condition and implemented safeguards to prevent recurrence. The network remains stable while we complete software upgrades and permanent remediation. Our current timeline of events is that the instability was triggered at approximately 19:09:21–27 UTC on July 29th 2026, and lasted for ~5 minutes. More updates and a complete RCA will be released in future updates.
- investigating Aug 12, 2026, 04:01 AM UTC
Teraswitch is investigating reports and alerts of similar issues affecting Internet connectivity.
- resolved Aug 18, 2026, 05:37 PM UTC
Teraswitch has completed remediations to remove the bug-triggering configurations from our routers, as well as upgrading our route reflectors and adding diverse vendors on routing software. These stabilizations have proven reliable since July 30th, when we have not seen any additonal invalid packets (IS-IS LSA advertisements) inside our backbone. We expect no further impacts from this issue.