conntrackd - netfilter connection tracking user-space daemon

       Pablo Neira Ayuso wrote and maintains the conntrackd tool

       Man page written by Pablo Neira Ayuso <pablo@netfilter.org>.

                                                  Apr 16, 2018                                     CONNTRACKD(8)

       Please,  report  them  to  netfilter-devel@vger.kernel.org  (subscription  required)  or  file  a  bug in
       Netfilter's bugzilla (https://bugzilla.netfilter.org).

       This daemon requires a Linux kernel version >= 2.6.18. TCP window tracking support  requires  >=  2.6.22,
       otherwise  you  have to disable it.  Helpers are fully supported since >= 2.6.25, however, if you use any
       previous version, depending on the protocol helper and  your  setup  (e.g.  if  you  setup  performs  NAT
       sequence adjustments or not), your help connection may be successfully recovered.

       There  are  several unsupported stateful iptables matches such as recent, connbytes and the quota matches
       which gather internal information to operate. Since that information does not belong to the domain of the
       connection tracking system, connections affected by those matches may not be fully recovered  during  the
       takeover.

       The  daemon requires a Linux kernel version >= 2.6.26 to support kernel-space event filtering. Otherwise,
       all the event filtering is done in userspace with the corresponding extra overhead. If you are not  using
       the Filter clause in the configuration file, ignore this notice.

conntrackd  is  the  user-space  daemon  for  the  netfilter  connection  tracking  system.  This  daemon
       synchronizes connection tracking states between several replica firewalls. Thus, conntrackd can  be  used
       to deploy highly available stateful firewalls.

       The daemon supports Primary-Backup and Multiprimary setups and can also be used as statistics collector.

       The exit code is 0 for correct function. Errors cause an exit code of 1.

       The  following  example  are  illustrative,  for  a  real use in a firewall fail-over, check the primary-
       backup.sh script that comes with the sources.

       conntrackd-d
              Runs conntrackd in daemon and synchronization mode

       conntrackd-i
              Dumps the states held in the internal cache, i.e. those handled by this firewall

       conntrackd-e
              Dumps the states held in the external cache, i.e. those handled by other replica firewalls

       conntrackd-c
              Commits the external cache into the kernel connection tracking system.  This is used to inject the
              state so that the connections can be recovered during the failover.

       During the 0.9.9 development, some important changes in the replication message format  were  introduced.
       Therefore, conntrackd >= 0.9.9 will not work appropriately with conntrackd <= 0.9.8.

       This should not be a problem if you use the same conntrackd version in all the firewall replica nodes.

       conntrackd - netfilter connection tracking user-space daemon

       The options recognized by conntrackd can be divided into two different groups.

   GEMERALOPTIONS
       General options for the conntrackd daemon.

       -d     Run conntrackd in daemon mode (fork to background).

       -C<path>
              Load config file specified in path. See conntrackd.conf(5) for details.

       -v     Display version information.

       -h     Display help information.

   CLIENTCOMMANDSconntrackd can be used in client mode to request several information and operations to a running instance
       of the daemon.

       -i[ct|expect]
              Dump the internal cache, i.e. show local states

       -e[ct|expect]
              Dump the external cache, i.e. show foreign states

       -x     Display output in XML format. This option is only valid in combination with -i and -e parameters.

       -f[internal|external]
              Flush the internal and/or external cache

       -F[ct|expect]
              Flush  the kernel conntrack table (if you use a Linux kernel >= 2.6.29, this option will not flush
              your internal and external cache).

       -c     Commit external cache to conntrack table.

       -B     Force a bulk send to other replica firewalls. With this command, you will ask conntrackd  to  send
              the state-entries that it owns to others.

       -n     Request resync with other node (only FT-FW and NOTRACK modes).

       -k     Kill the daemon

       -s[network|cache|runtime|link|rsqueue|process|queue|ct|expect]
              Dump statistics. If no parameter is passed, it displays the general statistics.
              If "network" is passed as parameter it displays the networking statistics.
              If "cache" is passed as parameter, it shows the extended cache statistics.
              If "runtime" is passed as parameter, it shows the run-time statistics.
              If "process" is passed as parameter, it shows existing child processes (if any).
              If "queue" is passed as parameter, it shows queue statistics.
              If "ct" is passed, it displays the general statistics.
              If "expect" is passed as parameter, it shows expectation statistics.

       -R[ct|expect]
              Force a resync against the kernel connection tracking table

       -t     Reset the in-kernel timers (See PurgeTimeout clause)

conntrackd.conf(5)conntrack(8)iptables(8)nft(8)http://conntrack-tools.netfilter.org

conntrackd[options]

       Starting  with  the 1.4.4 release, conntrackd includes integration with systemd(1) to use an unit file of
       Type=notify and watchdog support.