/usr/bin/routef is in iproute2 4.15.0-2ubuntu1.
This file is owned by root:root, with mode 0o755.
The actual contents of the file can be viewed below.
| 1 2 3 4 5 6 7 8 9 10 | #! /bin/sh
# SPDX-License-Identifier: GPL-2.0
if [ -z "$*" ] ; then
	exec ip -4 ro flush  scope global  type unicast
else
	echo "Usage: routef"
	echo
	echo "This script will flush the IPv4 routing table"
fi
 |