SV-221874r603260_rule
V-221874
SRG-OS-000480-GPOS-00227
OL07-00-040611
CAT II
10
Set the system to the required kernel parameter by adding the following line to "/etc/sysctl.conf" or a configuration file in the /etc/sysctl.d/ directory (or modify the line to have the required value):
net.ipv4.conf.all.rp_filter = 1
Issue the following command to make the changes take effect:
# sysctl --system
Verify the system uses a reverse-path filter for IPv4:
# grep net.ipv4.conf.all.rp_filter /etc/sysctl.conf /etc/sysctl.d/*
net.ipv4.conf.all.rp_filter = 1
If "net.ipv4.conf.all.rp_filter" is not configured in the /etc/sysctl.conf file or in the /etc/sysctl.d/ directory, is commented out, or does not have a value of "1", this is a finding.
Check that the operating system implements the accept source route variable with the following command:
# /sbin/sysctl -a | grep net.ipv4.conf.all.rp_filter
net.ipv4.conf.all.rp_filter = 1
If the returned line does not have a value of "1", this is a finding.
V-221874
False
OL07-00-040611
Verify the system uses a reverse-path filter for IPv4:
# grep net.ipv4.conf.all.rp_filter /etc/sysctl.conf /etc/sysctl.d/*
net.ipv4.conf.all.rp_filter = 1
If "net.ipv4.conf.all.rp_filter" is not configured in the /etc/sysctl.conf file or in the /etc/sysctl.d/ directory, is commented out, or does not have a value of "1", this is a finding.
Check that the operating system implements the accept source route variable with the following command:
# /sbin/sysctl -a | grep net.ipv4.conf.all.rp_filter
net.ipv4.conf.all.rp_filter = 1
If the returned line does not have a value of "1", this is a finding.
M
4089