'Ensure rp_filter is set to Strict mode.
rp_filter may be set to three values:
0 - Disabled
1 - Strict Reverse Path
2 - Loose Reverse Path
See https://www.kernel.org/doc/Documentation/networking/ip-sysctl.txt'

def testRPFilter(self):

    chk_id = 'CIS-NET-RP-FILTER'
    test_data = {'/proc/sys/net/ipv4/conf/default/rp_filter': '2'}
    host_data = self.GenFileData('LinuxProcSysHardeningSettings', test_data, self.parser)
    results = self.RunChecks(host_data)
    sym = 'Found:    System    does    not    perform    path    filtering.'
    found = ['net_ipv4_conf_default_rp_filter:    2']
    self.assertCheckDetectedAnom(chk_id, results, sym, found)
    test_data = {'/proc/sys/net/ipv4/conf/default/rp_filter': '1'}
    host_data = self.GenFileData('LinuxProcSysHardeningSettings', test_data, self.parser)
    results = self.RunChecks(host_data)
    self.assertCheckUndetected(chk_id, results)
