Verifying - The DDoS protection cluster has been back in normal operation since 01:33. As part of the analysis of the issue and the restoration of service, symmetric filtering remains temporarily disabled, as this was necessary to restore stable service. We strongly recommend that customers with access to the DDoS API leave it disabled until we have fully analyzed and resolved the situation. We currently expect to complete this tomorrow.
While work on the DDoS filters continues, redundancy and capacity remain reduced, but are sufficient for normal operation. We will update this post as soon as new information becomes available or further measures, maintenance, or restoration work are carried out. We will also provide a statement on today's issues.
Apr 22, 2026 - 02:06 CEST
Update - After bringing the DDoS protection cluster back into service at 21:08, we received reports of minor issues affecting some IPs with symmetric filtering enabled. As a result, we took the DDoS protection cluster out of production again and are actively working on a permanent solution. IPs without symmetric filtering enabled, which make up the majority, were not affected, as our fix for the core issue has proven effective.
Apr 21, 2026 - 21:26 CEST
Update - We are still working on restoring our DDoS protection cluster. Until then, attacks exceeding basic network-level protection cannot be fully mitigated. Basic protection remains in place all the time.
Apr 21, 2026 - 20:30 CEST
Update - After reverting the update, we observed additional issues affecting some connections at 16:56 and 17:08, each lasting approximately 30 seconds. In response, we immediately removed the DDoS filters from production. Restoring DDoS protection services remains our highest priority.
Apr 21, 2026 - 17:14 CEST
Update - After deploying the latest update, we observed issues affecting both established and new connections between 16:41 and 16:42.
We immediately rolled back the update to restore normal operation. We are currently investigating the root cause.
Apr 21, 2026 - 16:50 CEST
In progress - Scheduled maintenance is currently in progress. We will provide updates as necessary.
Apr 21, 2026 - 16:00 CEST
Scheduled - We will carry out maintenance on our DDoS protection infrastructure.

What we are doing
We will deploy software updates to our redundant DDoS scrubbing cluster. Filter appliances will be taken out of production and updated one by one to ensure mitigation capacity is always sufficient. After each update, functionality will be verified before we move on to the next filter.

Expected impact
No customer impact is expected at any datacenter, but it cannot be ruled out entirely. Idle (inactive) connections and sessions may time out; active ones should not, as they are expected to remain synchronized during the startup of a new software release. If you notice anything unusual – such as timeouts of active sessions or the inability to connect to your server – please contact our support immediately. We will continue monitoring new tickets for a while after the maintenance.

Affected customers
All IP prefixes routed through our DDoS protection (which is the default) are affected by this maintenance. Only prefixes that have been explicitly configured to bypass our DDoS protection (which we do not recommend) are unaffected. In any case, no customer action is required.

Fallback plan
Should the update fail and cause issues, we will disconnect the filters within a few seconds and update this status post transparently. In that case, mitigation of attacks will not be possible for 30-60 minutes while we prepare a rollback.