(kernel parameter ) net.ipv4.route.flush is a real-time on-demand sysctl key.

Kernel parameter: net.ipv4.route.flush

os version

• rhel5/6/7

The net.ipv4.route.flush key is a real-time on-demand sysct l key. It is used for point-in-time route cache flushing (See Diagnostic Steps section, below).

NOTE: This sysctl key cannot be used by placing an entry into /etc/sysctl.conf , and can only be used on-demand for point-in-time route cache flushing from the command line.

Reference

• How is the sysctl key net.ipv4.route.flush used in RHEL 5 and RHEL
  6?