diff --git a/conf/default_ports.conf b/conf/default_ports.conf
index a6ee932..e72b6be 100644
--- a/conf/default_ports.conf
+++ b/conf/default_ports.conf
@@ -30,6 +30,7 @@ standard_cups_port=$standard_ipp_port
 standard_print_raw_port=515
 standard_print_port=9100
 standard_remote_console_port=5900
+standard_checkmk_port=6556
 
 # - IPsec - Internet Security Association and
 # -  Key Management Protocol
diff --git a/conf/main_ipv4.conf.sample b/conf/main_ipv4.conf.sample
index 46caf3b..761fcad 100644
--- a/conf/main_ipv4.conf.sample
+++ b/conf/main_ipv4.conf.sample
@@ -852,6 +852,25 @@ declare -A munin_local_client_ip_arr
 munin_local_port=4949
 
 
+# ======
+# - Checkmk Monitoring Service (local network)
+# ======
+
+# - Checkmk Service Gateway (usually TCP port 6556)
+# -
+checkmk_service_gateway=false
+
+# - Checkmk Server local Networks (usually TCP port 6556)
+# -
+# - Blank separated list
+# -
+checkmk_local_server_ips=""
+
+# - checkmk Port
+# -
+checkmk_local_port="$standard_checkmk_port"
+
+
 # ======
 # - PowerChut Network Shutdown (PCNS)
 # ======
diff --git a/conf/main_ipv6.conf.sample b/conf/main_ipv6.conf.sample
index 47f5096..642e49d 100644
--- a/conf/main_ipv6.conf.sample
+++ b/conf/main_ipv6.conf.sample
@@ -818,6 +818,25 @@ declare -A munin_local_client_ip_arr
 munin_local_port=4949
 
 
+# ======
+# - Checkmk Monitoring Service (local network)
+# ======
+
+# - Checkmk Service Gateway (usually TCP port 6556)
+# -
+checkmk_service_gateway=false
+
+# - Checkmk Server local Networks (usually TCP port 6556)
+# -
+# - Blank separated list
+# -
+checkmk_local_server_ips=""
+
+# - checkmk Port
+# -
+checkmk_local_port="$standard_checkmk_port"
+
+
 # ======
 # - PowerChut Network Shutdown (PCNS)
 # ======
diff --git a/conf/post_decalrations.conf b/conf/post_decalrations.conf
index f92b650..d6ddb34 100644
--- a/conf/post_decalrations.conf
+++ b/conf/post_decalrations.conf
@@ -335,6 +335,14 @@ for _ip in $munin_local_server_ips ; do
    munin_local_server_ip_arr+=("$_ip")
 done
 
+# ---
+# - IP Adresses Checkmk Monitoring Service 
+# ---
+declare -a checkmk_local_server_ip_arr
+for _ip in $checkmk_local_server_ips ; do
+   checkmk_local_server_ip_arr+=("$_ip")
+done
+
 # ---
 # - IP Adresses XyMon
 # ---
diff --git a/ip6t-firewall-gateway b/ip6t-firewall-gateway
index f745bdf..0bd59a8 100755
--- a/ip6t-firewall-gateway
+++ b/ip6t-firewall-gateway
@@ -3665,6 +3665,56 @@ else
 fi
 
 
+# ---
+# - Checkmk Monitoring Service Gateway
+# ---
+
+echononl "\t\tCheckmk Monitoring Service Gateway (only local network)"
+
+if $checkmk_service_gateway ; then
+
+   for _dev in ${local_if_arr[@]} ; do
+      $ip6t -A OUTPUT -o $_dev -p tcp --dport $checkmk_local_port -m conntrack --ctstate NEW -j ACCEPT
+   done
+
+   echo_done
+else
+   echo_skipped
+fi
+
+
+# ---
+# - Checkmk Service local Networks
+# ---
+
+echononl "\t\tCheckmk Monitoring Service local Networks"
+if [[ ${#checkmk_local_server_ip_arr[@]} -gt 0 ]] ; then
+   for _ip in ${checkmk_local_server_ip_arr[@]} ; do
+      $ip6t -A INPUT -s $_ip -p tcp --dport $checkmk_local_port -m conntrack --ctstate NEW -j ACCEPT
+
+		if $kernel_forward_between_interfaces && ! $permit_between_local_networks ; then
+         for _dev in ${local_if_arr[@]} ; do
+            if ! $permit_between_local_networks ; then
+               $ip6t -A FORWARD -i $_dev -s $_ip -p tcp --dport $checkmk_local_port -m conntrack --ctstate NEW -j ACCEPT
+            fi
+         done
+      fi
+
+      # - Rule is needed if (local) interface aliases in use (like eth0:1)
+      # -
+      if $kernel_forward_between_interfaces && $local_alias_interfaces ; then
+         $ip6t -A FORWARD -p tcp -d $_ip --sport $checkmk_local_port --tcp-flag ACK ACK -j ACCEPT
+         $ip6t -A FORWARD -p tcp -s $_ip --dport $checkmk_local_port --tcp-flag ACK ACK -j ACCEPT
+      fi
+
+   done
+
+   echo_done
+else
+   echo_skipped
+fi
+
+
 # ---
 # - XyMon local service
 # ---
diff --git a/ipt-firewall-gateway b/ipt-firewall-gateway
index 3e138ef..638889b 100755
--- a/ipt-firewall-gateway
+++ b/ipt-firewall-gateway
@@ -4380,6 +4380,56 @@ else
 fi
 
 
+# ---
+# - Checkmk Monitoring Service Gateway
+# ---
+
+echononl "\t\tCheckmk Monitoring Service Gateway (only local network)"
+
+if $checkmk_service_gateway ; then
+
+   for _dev in ${local_if_arr[@]} ; do
+      $ipt -A OUTPUT -o $_dev -p tcp --dport $checkmk_local_port -m conntrack --ctstate NEW -j ACCEPT
+   done
+
+   echo_done
+else
+   echo_skipped
+fi
+
+
+# ---
+# - Checkmk Service local Networks
+# ---
+
+echononl "\t\tCheckmk Monitoring Service local Networks"
+if [[ ${#checkmk_local_server_ip_arr[@]} -gt 0 ]] ; then
+   for _ip in ${checkmk_local_server_ip_arr[@]} ; do
+      $ipt -A INPUT -s $_ip -p tcp --dport $checkmk_local_port -m conntrack --ctstate NEW -j ACCEPT
+
+      if $kernel_activate_forwarding && ! $permit_between_local_networks ; then
+         for _dev in ${local_if_arr[@]} ; do
+            if ! $permit_between_local_networks ; then
+               $ipt -A FORWARD -i $_dev -s $_ip -p tcp --dport $checkmk_local_port -m conntrack --ctstate NEW -j ACCEPT
+            fi
+         done
+      fi
+
+      # - Rule is needed if (local) interface aliases in use (like eth0:1)
+      # -
+      if $kernel_activate_forwarding && $local_alias_interfaces ; then
+         $ipt -A FORWARD -p tcp -d $_ip --sport $checkmk_local_port --tcp-flag ACK ACK -j ACCEPT
+         $ipt -A FORWARD -p tcp -s $_ip --dport $checkmk_local_port --tcp-flag ACK ACK -j ACCEPT
+      fi
+
+   done
+
+   echo_done
+else
+   echo_skipped
+fi
+
+
 # ---
 # - XyMon local service
 # ---