{
        local mp_prio_nr_tx=$1
        local mp_prio_nr_rx=$2
+       local mpj_syn=$3
+       local mpj_syn_ack=$4
        local count
 
        print_check "ptx"
        else
                print_ok
        fi
+
+       print_check "syn backup"
+       count=$(mptcp_lib_get_counter ${ns1} "MPTcpExtMPJoinSynBackupRx")
+       if [ -z "$count" ]; then
+               print_skip
+       elif [ "$count" != "$mpj_syn" ]; then
+               fail_test "got $count JOIN[s] syn with Backup expected $mpj_syn"
+       else
+               print_ok
+       fi
+
+       print_check "synack backup"
+       count=$(mptcp_lib_get_counter ${ns2} "MPTcpExtMPJoinSynAckBackupRx")
+       if [ -z "$count" ]; then
+               print_skip
+       elif [ "$count" != "$mpj_syn_ack" ]; then
+               fail_test "got $count JOIN[s] synack with Backup expected $mpj_syn_ack"
+       else
+               print_ok
+       fi
 }
 
 chk_subflow_nr()
                sflags=nobackup speed=slow \
                        run_tests $ns1 $ns2 10.0.1.1
                chk_join_nr 1 1 1
-               chk_prio_nr 0 1
+               chk_prio_nr 0 1 1 0
        fi
 
        # single address, backup
                        run_tests $ns1 $ns2 10.0.1.1
                chk_join_nr 1 1 1
                chk_add_nr 1 1
-               chk_prio_nr 1 1
+               chk_prio_nr 1 1 0 0
        fi
 
        # single address with port, backup
                        run_tests $ns1 $ns2 10.0.1.1
                chk_join_nr 1 1 1
                chk_add_nr 1 1
-               chk_prio_nr 1 1
+               chk_prio_nr 1 1 0 0
        fi
 
        if reset "mpc backup" &&
                speed=slow \
                        run_tests $ns1 $ns2 10.0.1.1
                chk_join_nr 0 0 0
-               chk_prio_nr 0 1
+               chk_prio_nr 0 1 0 0
        fi
 
        if reset "mpc backup both sides" &&
                speed=slow \
                        run_tests $ns1 $ns2 10.0.1.1
                chk_join_nr 0 0 0
-               chk_prio_nr 1 1
+               chk_prio_nr 1 1 0 0
        fi
 
        if reset "mpc switch to backup" &&
                sflags=backup speed=slow \
                        run_tests $ns1 $ns2 10.0.1.1
                chk_join_nr 0 0 0
-               chk_prio_nr 0 1
+               chk_prio_nr 0 1 0 0
        fi
 
        if reset "mpc switch to backup both sides" &&
                sflags=backup speed=slow \
                        run_tests $ns1 $ns2 10.0.1.1
                chk_join_nr 0 0 0
-               chk_prio_nr 1 1
+               chk_prio_nr 1 1 0 0
        fi
 }
 
                addr_nr_ns2=1 sflags=backup,fullmesh speed=slow \
                        run_tests $ns1 $ns2 10.0.1.1
                chk_join_nr 2 2 2
-               chk_prio_nr 0 1
+               chk_prio_nr 0 1 1 0
                chk_rm_nr 0 1
        fi
 
                sflags=nobackup,nofullmesh speed=slow \
                        run_tests $ns1 $ns2 10.0.1.1
                chk_join_nr 2 2 2
-               chk_prio_nr 0 1
+               chk_prio_nr 0 1 1 0
                chk_rm_nr 0 1
        fi
 }
                sflags=backup speed=slow \
                        run_tests $ns1 $ns2 10.0.1.1
                chk_join_nr 1 1 0
-               chk_prio_nr 0 0
+               chk_prio_nr 0 0 0 0
        fi
 
        # userspace pm type prevents rm_addr