redis-client and cluster of 3x2 nodes

vin-d@vin-d-UX305UA:~/redis$ ./redis-cli -c -p 6666
127.0.0.1:6666>
127.0.0.1:6666> cluster slots
1) 1) (integer) 0
   2) (integer) 5460
   3) 1) "127.0.0.1"
      2) (integer) 6666
      3) "9f71b95b15a662beb566762c5adb359fc0177a46"
   4) 1) "127.0.0.1"
      2) (integer) 6676
      3) "b50db8f6144b1ce18aec786621b934622ab6c65f"
2) 1) (integer) 5461
   2) (integer) 10922
   3) 1) "127.0.0.1"
      2) (integer) 6667
      3) "3c4cf7ae2bc22d14b31552f6979d5d7f668e8d87"
   4) 1) "127.0.0.1"
      2) (integer) 6677
      3) "2d63339b30e78b67bb9b96564d123437e2ecb011"
3) 1) (integer) 10923
   2) (integer) 16383
   3) 1) "127.0.0.1"
      2) (integer) 6668
      3) "559598b065279ff6ccc6bcb351f01ba87d8e305e"
   4) 1) "127.0.0.1"
      2) (integer) 6678
      3) "469a88af07383e2e1348947c4dd31e615e3b3e11"
127.0.0.1:6666> echo "now A2(tcp 6676) is off"
"now A2(tcp 6676) is off"
127.0.0.1:6666> cluster slots
1) 1) (integer) 0
   2) (integer) 5460
   3) 1) "127.0.0.1"
      2) (integer) 6666
      3) "9f71b95b15a662beb566762c5adb359fc0177a46"
2) 1) (integer) 5461
   2) (integer) 10922
   3) 1) "127.0.0.1"
      2) (integer) 6667
      3) "3c4cf7ae2bc22d14b31552f6979d5d7f668e8d87"
   4) 1) "127.0.0.1"
      2) (integer) 6677
      3) "2d63339b30e78b67bb9b96564d123437e2ecb011"
3) 1) (integer) 10923
   2) (integer) 16383
   3) 1) "127.0.0.1"
      2) (integer) 6668
      3) "559598b065279ff6ccc6bcb351f01ba87d8e305e"
   4) 1) "127.0.0.1"
      2) (integer) 6678
      3) "469a88af07383e2e1348947c4dd31e615e3b3e11"
127.0.0.1:6666> echo "now A2(tcp 6676) is back on"
"now A2(tcp 6676) is back on"
127.0.0.1:6666> cluster slots
1) 1) (integer) 0
   2) (integer) 5460
   3) 1) "127.0.0.1"
      2) (integer) 6666
      3) "9f71b95b15a662beb566762c5adb359fc0177a46"
   4) 1) "127.0.0.1"
      2) (integer) 6676
      3) "b50db8f6144b1ce18aec786621b934622ab6c65f"
2) 1) (integer) 5461
   2) (integer) 10922
   3) 1) "127.0.0.1"
      2) (integer) 6667
      3) "3c4cf7ae2bc22d14b31552f6979d5d7f668e8d87"
   4) 1) "127.0.0.1"
      2) (integer) 6677
      3) "2d63339b30e78b67bb9b96564d123437e2ecb011"
3) 1) (integer) 10923
   2) (integer) 16383
   3) 1) "127.0.0.1"
      2) (integer) 6668
      3) "559598b065279ff6ccc6bcb351f01ba87d8e305e"
   4) 1) "127.0.0.1"
      2) (integer) 6678
      3) "469a88af07383e2e1348947c4dd31e615e3b3e11"
127.0.0.1:6666> echo "now A1(tcp 6666) is off"
"now A1(tcp 6666) is off"
127.0.0.1:6666> cluster slots
Could not connect to Redis at 127.0.0.1:6666: Connection refused
not connected>
vin-d@vin-d-UX305UA:~/redis$ ./redis-cli -c -p 6667
127.0.0.1:6667> cluster slots
1) 1) (integer) 0
   2) (integer) 5460
   3) 1) "127.0.0.1"
      2) (integer) 6676
      3) "b50db8f6144b1ce18aec786621b934622ab6c65f"
2) 1) (integer) 5461
   2) (integer) 10922
   3) 1) "127.0.0.1"
      2) (integer) 6667
      3) "3c4cf7ae2bc22d14b31552f6979d5d7f668e8d87"
   4) 1) "127.0.0.1"
      2) (integer) 6677
      3) "2d63339b30e78b67bb9b96564d123437e2ecb011"
3) 1) (integer) 10923
   2) (integer) 16383
   3) 1) "127.0.0.1"
      2) (integer) 6668
      3) "559598b065279ff6ccc6bcb351f01ba87d8e305e"
   4) 1) "127.0.0.1"
      2) (integer) 6678
      3) "469a88af07383e2e1348947c4dd31e615e3b3e11"
127.0.0.1:6667> echo "now A1(tcp 6666) is still off and B1(6667) and C1(6668) are off too"
"now A1(tcp 6666) is still off and B1(6667) and C1(6668) are off too"
127.0.0.1:6667> cluster slots
Could not connect to Redis at 127.0.0.1:6667: Connection refused
not connected>
vin-d@vin-d-UX305UA:~/redis$ ./redis-cli -c -p 6676
127.0.0.1:6676> cluster slots
1) 1) (integer) 10923
   2) (integer) 16383
   3) 1) "127.0.0.1"
      2) (integer) 6678
      3) "469a88af07383e2e1348947c4dd31e615e3b3e11"
2) 1) (integer) 5461
   2) (integer) 10922
   3) 1) "127.0.0.1"
      2) (integer) 6677
      3) "2d63339b30e78b67bb9b96564d123437e2ecb011"
3) 1) (integer) 0
   2) (integer) 5460
   3) 1) "127.0.0.1"
      2) (integer) 6676
      3) "b50db8f6144b1ce18aec786621b934622ab6c65f"
127.0.0.1:6676>