Outage category: Blackboard
Location: Blackboard
Status: Closed
Resolved Alert:
Initial Symptoms
Received a notice from the Support Center via Team Chat.
Root Cause Analysis
Cause
DDoS attack on DNS servers. On April 20th, Anthology’s DNS servers experienced a targeted and excessive amount of DNS requests
which was intended to deny servicing DNS requests. DNS servers became overwhelmed and unable to
service requests.
Resolution
On April 25th, a change was executed to enhance our DNS services to prevent DDoS events. However, this change was not successful which propagated incorrect DNS information across the internet. The change was rolled back but DNS is a pull-based request and took time to propagate the correction across the internet.
Prevention
Anthology/Blackboard is planning to re-execute the upgrade to our DNS services to prevent issues
like the one experienced on 4/20. This change is targeted for Friday 4/28.