urgent

[ney25]

Hi NetPros,

anyone can help ?

Aug 20 17:19:44.160: %RTD-1-ADDR_FLAP: GigabitEthernet0/2 relearning 5 addrs per min

Aug 20 17:20:44.175: %RTD-1-ADDR_FLAP: GigabitEthernet0/1 relearning 6 addrs per min

switch>sh spann int gi 0/1

Interface Gi0/1 (port 40) in Spanning tree 1 is FORWARDING

Port path cost 4, Port priority 128

Designated root has priority 32768, address 0003.e35c.2580

Designated bridge has priority 32768, address 0003.e35c.2580

Designated port is 40, path cost 0

Timers: message age 0, forward delay 0, hold 0

BPDU: sent 1690479, received 1352

switch>sh spann int gi 0/2

Interface Gi0/2 (port 48) in Spanning tree 1 is FORWARDING

Port path cost 4, Port priority 128

Designated root has priority 32768, address 0003.e35c.2580

Designated bridge has priority 32768, address 0003.e35c.2580

Designated port is 48, path cost 0

Timers: message age 0, forward delay 0, hold 0

BPDU: sent 1703077, received 13968

regards,

kitten

[ney25]

Hi Bruno,

4 switches config file are there.

thanks.

[b.petronio]

Hi there,

The config u gave us, don't give me any clue.

Do u have any news ?

Best Regards,

Petr?nio

[ney25]

Hi Petronio

no, that what i have only :(

that's why i am very headache about how to find the loop from this network ?

[jorgenolla]

Hello:

It will help if you post the outcome of STP for each switch, this way we can see the STP topology; who is acting as the root bridge in each switch, and what states are the port on.

Best Regards

[ney25]

Hi Jorgenolla,

yes, that's what i wanted to do so.

p/s : switch 192.10.51.211 (Gi0/6) and 192.10.51.216 (Gi0/2) Port have been shut down.

Regards,

[avmabe]

You never set the root.

The 192.168.51.216 switch is currently the root bridge and that is not good.

Also, why not just plug all the devices straight into the 3750 and not the 51.211 box?

If I inherited this network, I'd plug all switches straight into the 3750 and make the 3759 the root bridge for the network.

[ney25]

Hi avmabe,

yes, i agreed with you but i can not change this design due to some " shit " reason.

so, what i can do is just find the root cause and cure the network now.

so, any suggestion and guidance ?

your reply will be highly appreciated.

[b.petronio]

Hi there,

I'm totaly agree with avmabe, unless u have physical contrains.

I cacn give u know a brief explanation, about why is 192.10.51.216 is assuming the root.

The Lower mac-address in each switch vlan 1, is the 192.10.51.216. (0003.e35c.2580).

And in each switch, they all have diferent cost's to the root, cause they have different paths.

I.E:

GigabitEthernet = Cost 4

210 to 216 = 4+4+4+4 = 16

211 to 216 = 4+4+4 = 12

212 to 216 = 4+4+4+4 = 16

213 to 216 = 4+4+4+4 = 16

214 to 216 = 4+4 = 8

215 to 216 = 4 = 4

So all the output u gave us, point to the root bridge on 192.10.51.216.

If u could try to do what avmabe said so.

Best Regards,

Bruno Petr?nio

[jorgenolla]

I needed to see the Topology as in Production mode not with the ports shut down. If you have shut down does ports, which the file you posted confirms; I will not be able to tell the actual working topology, and the problems on it.

If you can please post the STP output with Gi 0/6 on 51.211, and Gi 0/2 on 51.216 on.

Best Regards

[ney25]

Hi Jorgenolla,

sure, as requested.

51.211

-------

interface GigabitEthernet0/6

switchport mode dynamic desirable

shutdown

end

51.216

------

interface GigabitEthernet0/2

shutdown

end

p/s : actually this network very messy which no standard (dot1q) coz, some of them using (isl). does this will affect to the entire network as well ?

thanks

[jorgenolla]

Once the interfaces are up, STP will run STA, then the network will converge, after which you need to upload the output of all switches as you did before.

Best Regards

[ney25]

Hi Jorgenolla,

so, beside redesign the network, any idea how to cure this network ? coz, i believe some loop still in this network .

[jorgenolla]

I really need to see the STP topology in all switches, with all interfaces on no shut, to be able to give you any help.

[ney25]

Hi Jorgenolla,

attached with STP config for all switch.

but, i noticed the switch 51.215 , that's the root at Gi0/2, some more when i show interface trunk. i can't see the Gi0/2 as trunk , but it is connected to switch 51.216

switch#sh spann

VLAN0001

Spanning tree enabled protocol ieee

Root ID Priority 32768

Address 0003.e35c.2580

Cost 4

Port 50 (GigabitEthernet0/2)

Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Bridge ID Priority 32769 (priority 32768 sys-id-ext 1)

Address 000d.29b5.1640

Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Aging Time 300

Interface Role Sts Cost Prio.Nbr Type

---------------- ---- --- --------- -------- --------------------------------

Fa0/3 Desg FWD 19 128.3 P2p

Fa0/9 Desg FWD 19 128.9 P2p

Fa0/10 Desg FWD 19 128.10 P2p

Fa0/11 Desg FWD 19 128.11 P2p

Fa0/12 Desg FWD 19 128.12 P2p

Fa0/13 Desg FWD 19 128.13 P2p

Fa0/14 Desg FWD 19 128.14 P2p

Fa0/16 Desg FWD 19 128.16 P2p

Fa0/17 Desg FWD 19 128.17 P2p

Fa0/19 Desg FWD 19 128.19 P2p

Fa0/27 Desg FWD 19 128.27 Shr

Fa0/40 Desg FWD 19 128.40 P2p

Gi0/1 Desg FWD 4 128.49 P2p

Gi0/2 Root FWD 4 128.50 P2p

switch#sh int trunk

Port Mode Encapsulation Status Native vlan

Gi0/1 desirable 802.1q trunking 1

Port Vlans allowed on trunk

Gi0/1 1-4094

Port Vlans allowed and active in management domain

Gi0/1 1

Port Vlans in spanning tree forwarding state and not pruned

Gi0/1

1

*********************************************

Gi0/1 connected trunk a-full a-1000 1000BaseSX

Gi0/2 connected 1 a-full a-1000 1000BaseSX

regards,

kitten

[jorgenolla]

3524XL models do not support DTP (Dynamic Trunking Protocol), you must trunk all links to be trunk manually. This is something a lot of your switches are missing, according to the output you've posted!

I have attached a view of what ports should be Root Ports, and what ports should be in the Blocking state, in accordance with your lan diagram, and given no manual priority or cost changes have been made.

You've sent on your last post the state of the trunk ports, but you didn't send the

#show spanning-tree

command output for all switches. I need to see that in order to be able to tell you if spanning tree is working correctly.

Also ensure you have entered a lower priority on 51.216, by using the command:

#spanning-tree vlan 1 priority 4096

on the global config mode. this will ensure no changes on the Root Bridge for STP

Best Regards