# This configuration file is taken from Debian. # # /etc/sysctl.conf - Configuration file for setting system variables # See sysctl.conf (5) for information. # #kernel.domainname = example.com # Uncomment the following to stop low-level messages on console kernel.printk = 4 4 1 7 # Reboot X seconds after a kernel panic kernel.panic = 5 ##############################################################3 # Functions previously found in netbase # # Uncomment the next two lines to enable Spoof protection (reverse-path filter) # Turn on Source Address Verification in all interfaces to # prevent some spoofing attacks net.ipv4.conf.default.rp_filter=1 net.ipv4.conf.all.rp_filter=1 # Uncomment the next line to enable TCP/IP SYN cookies #net.ipv4.tcp_syncookies=1 # Uncomment the next line to enable packet forwarding for IPv4 #net.ipv4.ip_forward=1 # Uncomment the next line to enable packet forwarding for IPv6 #net.ipv6.conf.all.forwarding=1 ################################################################### # Additional settings - these settings can improve the network # security of the host and prevent against some network attacks # including spoofing attacks and man in the middle attacks through # redirection. Some network environments, however, require that these # settings are disabled so review and enable them as needed. # # Ignore ICMP broadcasts #net.ipv4.icmp_echo_ignore_broadcasts = 1 # # Set the runtime status of the net.ipv4.icmp_ignore_bogus_error_responses # kernel parameter to enable Kernel Parameter to Ignore Bogus ICMP Error # Responses on IPv4 Interfaces. # Ignoring bogus ICMP error responses reduces log size, although some # activity would not be logged. net.ipv4.icmp_ignore_bogus_error_responses = 1 # # Do not accept ICMP redirects (prevent MITM attacks) net.ipv4.conf.all.accept_redirects = 0 net.ipv6.conf.all.accept_redirects = 0 # _or_ # Accept ICMP redirects only for gateways listed in our default # gateway list (enabled by default) # Accepting "secure" ICMP redirects (from those gateways listed as default # gateways) has few legitimate uses. It should be disabled unless it is # absolutely required. net.ipv4.conf.all.secure_redirects = 0 # # Do not send ICMP redirects (we are not a router) net.ipv4.conf.all.send_redirects = 0 # # Do not accept IP source route packets (we are not a router) #net.ipv4.conf.all.accept_source_route = 0 net.ipv6.conf.all.accept_source_route = 0 # # Log Martian Packets #net.ipv4.conf.all.log_martians = 1 # #kernel.shmmax = 141762560 # WRL # set max socket memory ; default was 212992 net.core.rmem_max=425984 # WRS # The following kernel parameters help alleviate some RabbitMQ # connection issues. These values need to be set here to ensure sysinv-agent # remains connected to rabbitmq. Sysinv-agent starts before packstack and the # long default values allowed the connection to be lost for 2 hours. # Note the ipv4 vlaues are also applied to ipv6 connections. net.ipv4.tcp_keepalive_intvl = 1 net.ipv4.tcp_keepalive_probes = 5 net.ipv4.tcp_keepalive_time = 5 # This controls the tcp connection retries. # The default results in a delay of ~15 minutes before dead connections # to the floating ip are detected after a swact. # Reduce this delay to 8 shortens this to ~100 seconds. net.ipv4.tcp_retries2 = 8 # Reserve ports in the ephemeral port range: # # Incorporate the reserved keystone port (35357) from # /usr/lib/sysctl.d/openstack-keystone.conf # # Helm v2.13.1 hardcodes the following Tiller ports when installed in the # k8s cluster: 44134 (server), 44135 (probe), 44136 (trace). Reserve them # from the ephemeral port range. This will avoid potential port conflicts # that will cause the tiller pod to crash when the port is assigned to # another client/server net.ipv4.ip_local_reserved_ports=35357,44134-44136 # Set a global limit on the number of negative dentries. This is in units # of 0.1 %, so a value of 20 represents 2% of all memory. # We know of an issue with curl to an https endpoint when using nss versions # older than 3.52 which can cause unlimited negative dentry growth. We fixed # it in the code we control, but this will keep the number at a reasonable # size if an application is poorly behaved. fs.negative-dentry-limit=20 # Set the runtime status of the - net.ipv6.conf.default.accept_redirects - # kernel parameter to disable Kernel Parameter for Accepting ICMP Redirects # by Default on IPv6 Interfaces. # An illicit ICMP redirect message could result in a man-in-the-middle attack. net.ipv6.conf.default.accept_redirects = 0 # Set the runtime status of the net.ipv4.conf.default.accept_redirects kernel # parameter, to disable Kernel Parameter for Accepting ICMP Redirects by Default # on IPv4 Interfaces. # ICMP redirect messages are used by routers to inform hosts that a more direct # route exists for a particular destination. # These messages modify the host's route table and are unauthenticated. # An illicit ICMP redirect message could result in a man-in-the-middle attack. # This feature of the IPv4 protocol has few legitimate uses. It should be # disabled unless absolutely required. net.ipv4.conf.default.accept_redirects = 0 # Set the runtime status of the net.ipv4.conf.default.send_redirects kernel # parameter, to disable Kernel Parameter for Sending ICMP Redirects on all # IPv4 Interfaces by Default. # ICMP redirect messages are used by routers to inform hosts that a more # direct route exists for a particular destination. These messages contain # information from the system's route table possibly revealing portions of # the network topology. # The ability to send ICMP redirects is only appropriate for systems acting # as routers. net.ipv4.conf.default.send_redirects = 0 # Set the runtime status of the net.ipv6.conf.default.accept_ra kernel parameter # to disable Accepting Router Advertisements on all IPv6 Interfaces by Default # An illicit router advertisement message could result in a man-in-the-middle # attack. net.ipv6.conf.default.accept_ra = 0 # Set the runtime status of the net.ipv4.conf.default.secure_redirects kernel # parameter. # Accepting "secure" ICMP redirects (from those gateways listed as default # gateways) has few legitimate uses. # It should be disabled unless it is absolutely required. net.ipv4.conf.default.secure_redirects = 0 # Set the runtime status of the net.ipv6.conf.all.accept_ra kernel parameter. # An illicit router advertisement message could result in a man-in-the-middle # attack. net.ipv6.conf.all.accept_ra = 0 # Set the runtime status of the net.ipv4.conf.default.accept_source_route kernel # parameter. # Source-routed packets allow the source of the packet to suggest routers forward # the packet along a different path than configured on the router, which can be # used to bypass network security measures. # Accepting source-routed packets in the IPv4 protocol has few legitimate uses. # It should be disabled unless it is absolutely required, such as when IPv4 # forwarding is enabled and the system is legitimately functioning as a router. net.ipv4.conf.default.accept_source_route = 0 # Set the runtime status of the net.ipv6.conf.default.accept_source_route kernel # parameter. # Source-routed packets allow the source of the packet to suggest routers forward # the packet along a different path than configured on the router, which can be # used to bypass network security measures. This requirement applies only to the # forwarding of source-routerd traffic, such as when IPv6 forwarding is enabled # and the system is functioning as a router. # Accepting source-routed packets in the IPv6 protocol has few legitimate uses. # It should be disabled unless it is absolutely required. net.ipv6.conf.default.accept_source_route = 0