Настройки для увеличения безопасности:
  /sbin/sysctl -w net.ipv4.conf.all.send_redirects=0
  /sbin/sysctl -w net.ipv4.conf.all.accept_redirects=0
  /sbin/sysctl -w net.ipv4.conf.all.accept_source_route=0
  /sbin/sysctl -w net.ipv4.conf.all.mc_forwarding=0
  /sbin/sysctl -w net.ipv4.icmp_echo_ignore_broadcasts=1
  /sbin/sysctl -w net.ipv4.icmp_ignore_bogus_error_responses=1
  /sbin/sysctl -w net.ipv4.conf.all.log_martians=1
  /sbin/sysctl -w net.ipv4.conf.all.rp_filter=1