The Blackhole experiment blocks inbound and outbound network traffic. It works by dropping IP packets at the transport layer (Layer 4) of the OSI model. You can specify the types of traffic to impact using additional arguments, including port, hostname, and IP address.
Linux
The Blackhole Gremlin uses existing traffic policing features in the Linux Kernel to drop targeted IP packets.
This Gremlin does not interact with <span class="code-class-custom">iptables</span>, and so it does not interfere with any existing <span class="code-class-custom">iptables</span> rulesets.
This Gremlin requires the <span class="code-class-custom">NET_ADMIN</span> capability, which is enabled for Gremlin by default at installation time. See capabilities(7)
Windows
The Blackhole Gremlin uses the Windows Filtering Platform to drop targeted IP packets.
Options
| Parameter | Flag | Required | Default | Version | Description |
|---|
| IP Addresses | -i IP address | False | | 0.0.1 | Only impact traffic to these IP addresses. Also accepts CIDR values (i.e. 10.0.0.0/24). |
| Device | -d interfaces | False | Device discovery | 0.0.1 | Impact traffic over these network interfaces. Comma separated lists and multiple arguments supported. You can define multiple interfaces starting with agent version 2.30.0. |
| Hostnames | -h hostnames | False | ^api.gremlin.com | 0.0.1 | Only impact traffic to these hostnames. |
| Remote Ports | -p port numbers | False | ^53 | 0.0.1 | Impact outgoing and incoming traffic to and from these remote ports. Also accepts port ranges (e.g. 8080-8085). |
| Local Ports | -n port numbers | False | | 0.0.1 | Impact outgoing and incoming traffic to and from these local ports. Also accepts port ranges (e.g. 8080-8085). |
| Protocol | -P {TCP, UDP, ICMP} | False | all | 1.5.3 | Only impact a specific protocol. |
| Providers | WebUI and API Only | False | | 0.0.1 | External service providers to affect. |
| Tags | WebUI and API Only | False | | 0.0.1 | Only impact traffic to hosts running Gremlin clients associated with these tags. |
| Length | -l int | False | 60 | 0.0.1 | The length of the experiment (seconds). |