Network Interface Duplex Mismatch

Rule ID

PH_Rule_Avail_14

Default Status

Enabled

Description

Detects half/Full duplex mismatch on an network interface. This indicates configuration issues.

Severity

MITRE ATT&CK® Tactics

Network

MITRE ATT&CK® Techniques

No Technique Specified

Impacts

Network

Data Source

Cisco IOS via Syslog

Detection

Correlation

Remediation Guidance

Identify the root cause and solve the issue

Time Window

If the following pattern or patterns match an ingested event within the given time window in seconds, trigger an incident.

300 seconds

Trigger Conditions

If the following defined pattern/s occur within a 300 second time window.

IntfDuplexMismatch

SubPattern Definitions

SubPattern Name: IntfDuplexMismatch

This is the named definition of the event query, this is important if multiple subpatterns are defined to distinguish them.

SubPattern Query

This is the query logic that matches incoming events

eventType = "IOS-CDP-DUPLEX_MISMATCH" AND reptDevIpAddr IN (Group@PH_SYS_DEVICE_Network)

Group by Attributes

This defines how matching events are aggregated, only events with the same matching attribute values are grouped into one unique incident ID

reptDevIpAddr,srcIntfName,destName,destIntfName

Aggregate Constraint

This is most typically a numerical constraint that defines when the rule should trigger an incident

COUNT(*) > 5

Incident Attribute Mapping

This section defines which fields in matching raw events should be mapped to the incident attributes in the resulting incident.

The available raw event attributes to map are limited to the group by attributes and the aggregate event constraint fields for each subpattern

 srcIpAddr = IntfDuplexMismatch.reptDevIpAddr,
srcIntfName = IntfDuplexMismatch.srcIntfName,
destName = IntfDuplexMismatch.destName,
destIntfName = IntfDuplexMismatch.destIntfName

FortiSIEM Rules