Spanning tree

dacruzer1 · ‎05-21-2010

I am trying to troubleshoot a loop in my network and I may have found the problem. Below is the output of the spanning tree on a switch

CompRmSw05#sh spanning-tree root

                                        Root    Hello Max Fwd
Vlan                   Root ID          Cost    Time Age Dly Root Port
---------------- -------------------- --------- ----- --- --- ------------
VLAN0001         32769 000a.4144.1200        16    2   20 15 Gi4/0/25
VLAN0010         32778 000a.4144.1200        16    2   20 15 Gi4/0/25
VLAN0011         32779 000a.4144.1200        16    2   20 15 Gi4/0/25
VLAN0012         32780 000a.4144.1200        16    2   20 15 Gi4/0/25
VLAN0064         32769 000a.4144.1200        20    2   20 15 Gi4/0/1
VLAN0065         32833 000a.4144.1200        16    2   20 15 Gi4/0/25
VLAN0068         32836 000a.4144.1200        16    2   20 15 Gi4/0/25
VLAN0069         32837 000a.4144.1200        16    2   20 15 Gi4/0/25
VLAN0071         32839 000a.4144.1200        16    2   20 15 Gi4/0/25
VLAN0072         32840 000a.4144.1200        16    2   20 15 Gi4/0/25
VLAN0079         32847 000a.4144.1200        16    2   20 15 Gi4/0/25
VLAN0084         32852 000a.4144.1200        16    2   20 15 Gi4/0/25

I want the root port of VLAN64 (in bold) to go to Gi4/0/25.

If I shut down Gi4/0/1 and reload the switch. Does anyone know if this will fix my loop and VLAN64 will force to go to Gi4/0/25?

Thanks

Alfred

merryllem · ‎05-21-2010

Can you post a "show int trunk" output?. Diagrams also help if you have it.

dacruzer1 · ‎05-21-2010

I have attached a diagram and below is the "sh int trunk"

Thanks

CompRmSw05#sh int trunk

Port        Mode             Encapsulation Status        Native vlan
Gi1/0/4     on               802.1q         trunking      1
Gi1/0/5     on               802.1q         trunking      1
Gi1/0/6     on               802.1q         trunking      1
Gi1/0/7     on               802.1q         trunking      1
Gi1/0/16    on               802.1q         trunking      1
Gi1/0/22    on               802.1q         trunking      1
Gi2/0/11    on               802.1q         trunking      1
Gi2/0/12    on               802.1q         trunking      1
Gi2/0/13    on               802.1q         trunking      1
Gi2/0/14    on               802.1q         trunking      1
Gi2/0/18    on               802.1q         trunking      1
Gi2/0/19    on               802.1q         trunking      1
Gi4/0/25    on               802.1q         trunking      1

Port        Vlans allowed on trunk
Gi1/0/4     1-4094
Gi1/0/5     1-4094
Gi1/0/6     1-4094
Gi1/0/7     1-4094
Gi1/0/16    1-4094
Gi1/0/22    1-4094
Gi2/0/11    1-4094
Gi2/0/12    1-4094
Gi2/0/13    1-4094
Gi2/0/14    1-4094
Gi2/0/18    1-4094
Gi2/0/19    1-4094
Gi4/0/25    1-4094

Port        Vlans allowed and active in management domain
Gi1/0/4     1,10-12,64-65,68-69,71-72,79,84-85,95-96,98,104,107,111,192,200-201,300-302,853
Gi1/0/5     1,10-12,64-65,68-69,71-72,79,84-85,95-96,98,104,107,111,192,200-201,300-302,853
Gi1/0/6     1,10-12,64-65,68-69,71-72,79,84-85,95-96,98,104,107,111,192,200-201,300-302,853
Gi1/0/7     1,10-12,64-65,68-69,71-72,79,84-85,95-96,98,104,107,111,192,200-201,300-302,853
Gi1/0/16    1,10-12,64-65,68-69,71-72,79,84-85,95-96,98,104,107,111,192,200-201,300-302,853
Gi1/0/22    1,10-12,64-65,68-69,71-72,79,84-85,95-96,98,104,107,111,192,200-201,300-302,853
Gi2/0/11    1,10-12,64-65,68-69,71-72,79,84-85,95-96,98,104,107,111,192,200-201,300-302,853
Gi2/0/12    1,10-12,64-65,68-69,71-72,79,84-85,95-96,98,104,107,111,192,200-201,300-302,853
Gi2/0/13    1,10-12,64-65,68-69,71-72,79,84-85,95-96,98,104,107,111,192,200-201,300-302,853
Gi2/0/14    1,10-12,64-65,68-69,71-72,79,84-85,95-96,98,104,107,111,192,200-201,300-302,853
Gi2/0/18    1,10-12,64-65,68-69,71-72,79,84-85,95-96,98,104,107,111,192,200-201,300-302,853
Gi2/0/19    1,10-12,64-65,68-69,71-72,79,84-85,95-96,98,104,107,111,192,200-201,300-302,853
Gi4/0/25    1,10-12,64-65,68-69,71-72,79,84-85,95-96,98,104,107,111,192,200-201,300-302,853

Port        Vlans in spanning tree forwarding state and not pruned
Gi1/0/4     1,10-12,64-65,68-69,71-72,79,84-85,95-96,98,104,107,111,192,200-201,300-302,853
Gi1/0/5     1,10-12,64-65,68-69,71-72,79,84-85,95-96,98,104,107,111,192,200-201,300-302,853
Gi1/0/6     1,10-12,64-65,68-69,71-72,79,84-85,95-96,98,104,107,111,192,200-201,300-302,853
Gi1/0/7     1,10-12,64-65,68-69,71-72,79,84-85,95-96,98,104,107,111,192,200-201,300-302,853
Gi1/0/16    1,10-12,64-65,68-69,71-72,79,84-85,95-96,98,104,107,111,192,200-201,300-302,853
Gi1/0/22    1,10-12,64-65,68-69,71-72,79,84-85,95-96,98,104,107,111,192,200-201,300-302,853
Gi2/0/11    1,10-12,64-65,68-69,71-72,79,84-85,95-96,98,104,107,111,192,200-201,300-302,853
Gi2/0/12    1,10-12,64-65,68-69,71-72,79,84-85,95-96,98,104,107,111,192,200-201,300-302,853
Gi2/0/13    1,10-12,64-65,68-69,71-72,79,84-85,95-96,98,104,107,111,192,200-201,300-302,853
Gi2/0/14    1,10-12,64-65,68-69,71-72,79,84-85,95-96,98,104,107,111,192,200-201,300-302,853
Gi2/0/18    1,10-12,64-65,68-69,71-72,79,84-85,95-96,98,104,107,111,192,200-201,300-302,853
Gi2/0/19    1,10-12,64-65,68-69,71-72,79,84-85,95-96,98,104,107,111,192,200-201,300-302,853
Gi4/0/25    1,10-12,64-65,68-69,71-72,79,84-85,95-96,98,104,107,111,192,200-201,300-302,853
CompRmSw05#

ramji_avinash · ‎05-23-2010

I think u have to change the port-priority or the cost !!!!!

First it should be cost or the priority

might be the following command

spanning tree vlan 64 port-priority

spanning tree valn 64 cost