diff --git a/ip6t-firewall-gateway b/ip6t-firewall-gateway
index e4bd82b..d6bccbc 100755
--- a/ip6t-firewall-gateway
+++ b/ip6t-firewall-gateway
@@ -2335,6 +2335,12 @@ if $kernel_forward_between_interfaces && ! $permit_between_local_networks && $al
          fi
          $ip6t -A FORWARD -i $_local_dev_1 -o $_local_dev_2 -p tcp --dport $standard_cups_port -m conntrack --ctstate NEW -j ACCEPT
       done
+
+      if $local_alias_interfaces ; then
+         $ip6t -A FORWARD -o $_local_dev_1 -p tcp --dport $standard_cups_port --tcp-flag ACK ACK -j ACCEPT
+         $ip6t -A FORWARD -o $_local_dev_1 -p tcp --sport $standard_cups_port --tcp-flag ACK ACK -j ACCEPT
+      fi
+
    done
    echo_done
 else
@@ -2356,6 +2362,12 @@ if $kernel_forward_between_interfaces && ! $permit_between_local_networks && $al
          fi
          $ip6t -A FORWARD -i $_local_dev_1 -o $_local_dev_2 -p tcp --dport $standard_print_port -m conntrack --ctstate NEW -j ACCEPT
       done
+
+      if $local_alias_interfaces ; then
+         $ip6t -A FORWARD -o $_local_dev_1 -p tcp --dport $standard_print_port --tcp-flag ACK ACK -j ACCEPT
+         $ip6t -A FORWARD -o $_local_dev_1 -p tcp --sport $standard_print_port --tcp-flag ACK ACK -j ACCEPT
+      fi
+
    done
    echo_done
 else
@@ -2377,6 +2389,12 @@ if $kernel_forward_between_interfaces && ! $permit_between_local_networks && $al
          fi
          $ip6t -A FORWARD -i $_local_dev_1 -o $_local_dev_2 -p tcp --dport $standard_print_raw_port -m conntrack --ctstate NEW -j ACCEPT
       done
+
+      if $local_alias_interfaces ; then
+         $ip6t -A FORWARD -o $_local_dev_1 -p tcp --dport $standard_print_raw_port --tcp-flag ACK ACK -j ACCEPT
+         $ip6t -A FORWARD -o $_local_dev_1 -p tcp --sport $standard_print_raw_port --tcp-flag ACK ACK -j ACCEPT
+      fi
+
    done
    echo_done
 else
diff --git a/ipt-firewall-gateway b/ipt-firewall-gateway
index 37404fe..5a4de3d 100755
--- a/ipt-firewall-gateway
+++ b/ipt-firewall-gateway
@@ -2756,6 +2756,12 @@ if $kernel_activate_forwarding && ! $permit_between_local_networks && $allow_pri
          fi
          $ipt -A FORWARD -i $_local_dev_1 -o $_local_dev_2 -p tcp --dport $standard_cups_port -m conntrack --ctstate NEW -j ACCEPT
       done
+
+      if $local_alias_interfaces ; then
+         $ipt -A FORWARD -o $_local_dev_1 -p tcp --dport $standard_cups_port --tcp-flag ACK ACK -j ACCEPT
+         $ipt -A FORWARD -o $_local_dev_1 -p tcp --sport $standard_cups_port --tcp-flag ACK ACK -j ACCEPT
+      fi
+
    done
    echo_done
 else
@@ -2777,6 +2783,12 @@ if $kernel_activate_forwarding && ! $permit_between_local_networks && $allow_pri
          fi
          $ipt -A FORWARD -i $_local_dev_1 -o $_local_dev_2 -p tcp --dport $standard_print_port -m conntrack --ctstate NEW -j ACCEPT
       done
+
+      if $local_alias_interfaces ; then
+         $ipt -A FORWARD -o $_local_dev_1 -p tcp --dport $standard_print_port --tcp-flag ACK ACK -j ACCEPT
+         $ipt -A FORWARD -o $_local_dev_1 -p tcp --sport $standard_print_port --tcp-flag ACK ACK -j ACCEPT
+      fi
+
    done
    echo_done
 else
@@ -2798,6 +2810,12 @@ if $kernel_activate_forwarding && ! $permit_between_local_networks && $allow_pri
          fi
          $ipt -A FORWARD -i $_local_dev_1 -o $_local_dev_2 -p tcp --dport $standard_print_raw_port -m conntrack --ctstate NEW -j ACCEPT
       done
+
+      if $local_alias_interfaces ; then
+         $ipt -A FORWARD -o $_local_dev_1 -p tcp --dport $standard_print_raw_port --tcp-flag ACK ACK -j ACCEPT
+         $ipt -A FORWARD -o $_local_dev_1 -p tcp --sport $standard_print_raw_port --tcp-flag ACK ACK -j ACCEPT
+      fi
+
    done
    echo_done
 else