Triggered when ASM detects that a request violates an ASM security policy for Denial of Service attacks
As of 11.3, this event replaces the VIOLATION_DOS_ATTACK_STARTED event and the ATTACK_TYPE_DOS_ATTACK_STARTED attack type.
The event is invoked on each HTTP request that is involved in a DoS attack–that is, a request that comes from a suspicious client IP address or destined to a suspicious URL with the exception of the following:
  1. When the attack prevention mode is CS challenge (client IP address or requested URL) the event is not triggered for any request.
  2. When in CAPTCHA or rate limit mode (client IP address or requested URL) the event is invoked only for attack requests that are not dropped.

When in transparent mode, the event is invoked for every request. This is the most common intended use case for this event: enabling the administrator to implement a proprietary prevention policy.
Variable name Variable description
$DOSL7_ATTACKER_IP The attacker IP address
$DOSL7_MITIGATION Mitigation method which is applied on the current HTTP request


Deprecated in BIG-IP Next v20.0.1


    log local0. "Attacker IP: $DOSL7_ATTACKER_IP"
    log local0. "Mitigation: $DOSL7_MITIGATION"
log example from /var/log/ltm
Aug 23 05:44:40 tmm info tmm[17073]: Rule /Common/dosl7_irule : Attacker IP:
Aug 23 05:44:40 tmm info tmm[17073]: Rule /Common/dosl7_irule : Mitigation: Source IP-Based Rate Limiting