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Linux network duplication

Linux network duplication injects chaos to disrupt network connectivity by duplicating network packets on a Linux machine.

Linux network duplication

Use cases​

Linux network duplication:

  • Induces network duplication on the target Linux machines.
  • Simulates packet duplication in the network.
note
  • This fault can be executed on Ubuntu 16 or higher, Debian 10 or higher, CentOS 7 or higher, RHEL 7 or higher, Fedora 30 or higher, and openSUSE LEAP 15.4 or higher.
  • The linux-chaos-infrastructure systemd service should be in an active state, and the infrastructure should be in CONNECTED state.

Fault permissions​

The fault uses the root Linux user and root user group.

Mandatory tunables​

Tunable Description Notes
networkInterfaces Comma-separated values of target network interfaces. For example, eth0,ens192.

Optional tunables​

Tunable Description Notes
destinationHosts List of the target host names or keywords. For example, google.com,litmuschaos.io. If neither destinationHosts nor destinationIPs is present, the fault injects chaos for all host names or domains.
destinationIPs List of comma-separated target IPs. Also supports a list of target destination ports for a given IP, that are separated by a pipe (|). For example, 1.1.1.1,35.24.108.92|3000|8080. If neither destinationHosts nor destinationIPs is provided, all host names or domains are targeted.
packetDuplicationPercentage Percentage of packets to duplicate. For example, 50. Default: 100%
sourcePorts Source ports to be filtered for chaos. For example: 5000,8080 . Alternatively, the ports can be whitelisted, that is, filtered to be exempt from chaos. Prepend a ! to the list of ports to be exempted. For example, !5000,8080 .
destinationPorts Destination ports to be filtered for chaos. For example, 5000,8080 . Alternatively, the ports can be whitelisted, that is, filtered to be exempt from chaos. Prepend a ! to the list of ports to be exempted. For example, !5000,8080 .
whitelistSSH Specifies whether the SSH connectivity should be retained during the chaos in the target machine. Default: true. Supports one of: true, false
duration Duration through which chaos is injected into the target resource. Should be provided in [numeric-hours]h[numeric-minutes]m[numeric-seconds]s format. Default: 30s. Examples: 1m25s, 1h3m2s, 1h3s
rampTime Period to wait before and after injecting chaos. Should be provided in [numeric-hours]h[numeric-minutes]m[numeric-seconds]s format. Default: 0s. Examples: 1m25s, 1h3m2s, 1h3s

Destination hosts​

The destinationHosts input variable subjects the comma-separated names of the target hosts to chaos.

The following YAML snippet illustrates the use of this input variable:

apiVersion: litmuchaos.io/v1alpha1
kind: LinuxFault
metadata:
  name: linux-network-duplication
  labels:
    name: network-duplication
spec:
  networkChaos/inputs:
    destinationHosts: 'google.com'
    networkInterfaces: "eth0"

Destination IPs​

The destinationIPs input variable subjects the comma-separated names of the target IPs to chaos. You can specify the ports to be targeted for an IP by using a pipe (|) as a separator. While providing ports is optional, omitting them will affect all the ports associated with the destination IPs.

The following YAML snippet illustrates the use of this input variable:

apiVersion: litmuchaos.io/v1alpha1
kind: LinuxFault
metadata:
  name: linux-network-duplication
  labels:
    name: network-duplication
spec:
  networkChaos/inputs:
    destinationIPs: '1.1.1.1,192.168.5.6|80|8080'
    networkInterfaces: "eth0"

Source and destination ports​

By default, the network experiments disrupt traffic for all the source and destination ports. Tune the interruption of specific port(s) using sourcePorts and destinationPorts inputs, respectively.

  • sourcePorts: Ports of the target application whose accessibility is impacted.
  • destinationPorts: Ports of the destination services or pods or the CIDR blocks(range of IPs) whose accessibility is impacted.

The following YAML snippet illustrates the use of this input variable:

apiVersion: litmuchaos.io/v1alpha1
kind: LinuxFault
metadata:
  name: linux-network-duplication
  labels:
    name: network-duplication
spec:
  networkChaos/inputs:
    destinationIPs: '1.1.1.1'
    networkInterfaces: "eth0"
    sourcePorts: "8080,3000"
    destinationPorts: "5000,3000"

Ignore source and destination ports​

By default, the network experiments disrupt traffic for all the source and destination ports. Ignore the specific ports using sourcePorts and destinationPorts inputs, respectively.

  • sourcePorts: Provide source ports that are not subject to chaos as comma-separated values preceded by !.
  • destinationPorts: Provide destination ports that are not subject to chaos as comma-separated values preceded by !.

The following YAML snippet illustrates the use of this input variable:

apiVersion: litmuchaos.io/v1alpha1
kind: LinuxFault
metadata:
  name: linux-network-duplication
  labels:
    name: network-duplication
spec:
  networkChaos/inputs:
    destinationIPs: '1.1.1.1'
    networkInterfaces: "eth0"
    sourcePorts: "!8080,3000"
    destinationPorts: "!5000,3000"

Packet duplication percentage​

The packetDuplicationPercentage input variable duplicates a specific percentage of the data packets.

The following YAML snippet illustrates the use of this input variable:

apiVersion: litmuchaos.io/v1alpha1
kind: LinuxFault
metadata:
  name: linux-network-duplication
  labels:
    name: network-duplication
spec:
  networkChaos/inputs:
    packetDuplicationPercentage: '50'
    networkInterfaces: "eth0"