Cases3 cases
1 to 3 of 3
IL-0225An IGP purge command made every Microsoft WAN router recompute routes, causing global latency, timeouts and packet lossMicrosoft Azure2023- Symptoms
From 07:08 UTC on 25 January 2023, customers saw long network latency and timeouts when connecting to resources in Azure regions and to other Microsoft services such as Microsoft 365 and Power Platform. Microsoft's monitoring detected DNS and WAN issues from 07:11 UTC.
- Trigger
A network engineer adding capacity to the global WAN in Madrid ran a step of a recently changed standard operating procedure that purged the IGP database; on the router manufacturer involved, that command runs on all IGP-joined routers instead of only the local one.
- Root cause
- Component
- Contributing factor
- Detection
Monitoring detected DNS and WAN issues from 07:11 UTC and alerted the on-call engineers within 5 minutes of the command being run. The team reviewed all recent changes and identified the command by 08:20 UTC. The engineer making the change was not informed of the alerts because of the unqualified changes to the SOP.
- Remediation
- Restarted by hand the paused WAN health and traffic engineering systems, which ended the remaining packet loss
- Action items
- Audit and block similar widespread-impact commands across all three vendors for all WAN router roles
- Give on-call engineers real-time visibility of approved and unqualified activity on network devices
- Run regular mandatory operational training and attestation of following all SOPs
- Have the Change Advisory Board review all SOPs still pending qualification within 30 days
IL-0539KT's internet service failed nationwide for about 89 minutes as wrong routes spread from one router in BusanKT2021- Symptoms
On 25 October 2021 from about 11:16, traffic to the DNS servers in KT's network rose sharply, and then KT's internet service failed across the whole country. KT recognised the internet outage at 11:20, and the outage lasted about 89 minutes until KT finished recovery at about 12:45.
- Trigger
During the replacement of an enterprise network router at KT's Busan office, worked on remotely from the Busan communication center, a worker entered a routing configuration script that lacked the 'exit' command that should have ended the IS-IS part of the configuration.
- Root cause
- Component
- Contributing factor
- Detection
KT recognised the internet outage at 11:20, four minutes after DNS traffic began to surge at 11:16. The Ministry of Science and ICT saw the traffic increase in its own monitoring, and KT reported the outage to the ministry at 11:40.
- Remediation
- Isolated the router where the faulty routing configuration was entered
- Logged in to each regional router, deleted the faulty processes and restarted them
- Action items
- Check the network management of major carriers, including their work procedures and the systems that stop technical errors from spreading
- Consider having major carriers introduce simulation systems that diagnose errors from network work in advance
- Have the NMS center and network operations center of each major carrier check technically that approved work plans are followed
- Strengthen safeguards in routing work, such as limiting the number of route entries updated at once below a set level
- Strengthen the monitoring of carriers' outages and develop technology, including AI-based preventive diagnosis, for network stability and resilience
- Prepare structural measures for a stable network architecture and network survivability
- Let carriers notify users of outages through SNS, text messages and other means, not only the website
- Lessons
The investigation named management problems and technical problems. On the management side, work approved for the night was done during the day, partner company workers did the routing work without a work manager, and the work was done with the network still connected. On the technical side, the two pre-verification steps were people reading the script and missed the missing 'exit', there was no virtual testbed for trying the work on a disconnected network, and nothing stopped an error in one region from spreading to the whole country.
IL-0228IPv4 routing across OVHcloud's global network broke after a router change put the full internet routing table into OSPFOVHcloud2021- Symptoms
At 09:20 CET on 13 October 2021, during a planned change on a router, IPv4 traffic across OVHcloud's whole network stopped being routed, while all IPv6 traffic stayed reachable. The team detected a problem with the router's performance at 09:21 CET and escalated at once.
- Trigger
A planned change to a router in the Vint Hill datacentre in the United States, meant to strengthen anti-DDoS protection, included a command to regulate the redistribution of BGP into OSPF, and the router did not interpret that command correctly.
- Root cause
- Component
- Contributing factor
- Detection
At 09:21 CET the team detected a problem with the router's performance and started the escalation process.
- Remediation
- Disconnected the optical equipment to isolate the router's connectivity
- Powered off the faulty router
- Stabilised connectivity to restore the remaining services
- Action items
- Re-evaluate the change procedure for this type of equipment, which applies the command line natively
- Strengthen the related change process
These 3 cases involve BGP routing and Interior routing (IGP). kubegap audits a Kubernetes cluster for gaps like these, read-only, from Claude Code or Codex; its checks cite public reports like the ones in this library.
By root cause1
Configuration change3 cases
- Contributing factor
- Organisation
IL-0225An IGP purge command made every Microsoft WAN router recompute routes, causing global latency, timeouts and packet lossMicrosoft Azure2023IL-0539KT's internet service failed nationwide for about 89 minutes as wrong routes spread from one router in BusanKT2021IL-0228IPv4 routing across OVHcloud's global network broke after a router change put the full internet routing table into OSPFOVHcloud2021