Sysctl

The sysctl statement allows configuring network-related sysctl settings which are not interface specific.

• sysctl.all - configures all interface-specific settings
• sysctl.default - configures the interface-specific default settings
• sysctl.mpls - configures MPLS1 settings
• sysctl.mptcp - configures MPTCP2 settings

Schema description

# https://www.kernel.org/doc/Documentation/networking/ip-sysctl.txt
sysctl:
  all:
    # /proc/sys/net/ipv4/conf/all/
    ipv4:
      forwarding: 1
  default:
    # /proc/sys/net/ipv4/conf/default/
    ipv4:
      forwarding: 1

  # /proc/sys/net/mpls/
  # https://www.kernel.org/doc/Documentation/networking/mpls-sysctl.txt
  mpls:
    # set greater 0 to enable mpls forwarding
    platform_labels: 1024

The settings can be also configured inside of namespaces.

sysctl: &my-sysctl
  all:
    ipv6:
      forwarding: 1
# …
namespaces:
  guests:
    sysctl: *my-sysctl
    # …

Examples:

• sysctl interface settings

Free-Form Configuration

The sysctl setting allows configuring settings explicitly supported in IfState, only. The sysctl_conf setting allows specifying any sysctl settings in the sysctl.conf configuration format.

It is possible to use YaML multiline strings or read the settings from a file using the !include tag. All settings need to be children of the net namespace. It is also possible to add empty and comment lines for convenience reasons:

sysctl_conf: |
  # double the max. number of conntrack entries
  net.nf_conntrack_max = 524288

  # change the default queuing discipline to CAKE
  net.core.default_qdisc = cake