Getting this syslog message on almost all the MX routers:

DDOS_PROTOCOL_VIOLATION_SET: Protocol Rejectv6:aggregate is violated

This happen when a packet is sent toward an IP that is part of an aggregate route, but not part of a more specific route.
For example port scan on whole ranges, etc...

The default behavior for the router is to reply to that request with a reject packet, which could lead to overwhelming the router if sent in high amount.

The recommended fix is to silently ignore it:

[edit routing-options aggregate]
+    defaults {
+        discard;
+    }