System Control

sysctl

Reads/sets kernel settings from the virtual /proc file system.
Values can be edited directly with echo 1/0 >> /proc/net/ipv6/conf/all/disable_ipv6 or by editing /etc/sysctl.conf or /etc/sysctl.d/parameter.

Settings

sysctl -a list all settings
sysctl -a | grep net.ipv6.conf.all.disable_ipv6 list specific setting
sysctl net.ipv6.conf.all.disable_ipv6 list specific setting
sysctl -w parameter=value change $parameter to $value
sysctl -p reload settings