Topology change every 1h

[Adam]

Hello together,
we have a big problem on our network, topology change takes place every hour and in the morning sometimes every 3 minutes.
We use RSTP and BPDU on all edge Ports.
We have 2 Core S8 and about 50 Stacks with B2, B3 and B5, altogether about 150 Enterasys switches.
Both S8 are with 2x10Gbit connected together to a lag.0.1 with all vlans

First S8 is the Root Bridge

Designated Root Priority - 4096
Designated Root Cost - 0
Designated Root Port - 0
Root Max Age - 20 sec
Root Hello Time - 2 sec
Root Forward Delay - 15 sec
Bridge ID MAC Address - xx
Bridge ID Priority - 4096
Bridge Max Age - 20 sec
Bridge Hello Time - 2 sec
Bridge Forward Delay - 15 sec
Topology Change Count - 24778
Time Since Top Change - 00 days 00:35:02
Max Hops - 20

Second S8

Designated Root Priority - 4096
Designated Root Cost - 1
Designated Root Port - lag.0.1
Root Max Age - 20 sec
Root Hello Time - 2 sec
Root Forward Delay - 15 sec
Bridge ID MAC Address - xx
Bridge ID Priority - 8192
Bridge Max Age - 20 sec
Bridge Hello Time - 2 sec
Bridge Forward Delay - 15 sec
Topology Change Count - 24755
Time Since Top Change - 00 days 00:35:02
Max Hops - 20

Our Problem is that the Topology change doesn´t match all Stacks, there are only 17/50 and both Cores which are doing that. We disabled the complete redundancy and it still happens even there where only one stack is connected to both Cores...

How can we find out who causes this Topology change?

All other topics here didn´t help us.

Thanks for help
greets

[Adam]

first at all thanks for your help and usefull hints.
I found some interesting things...

when Core 1 shows topology change
<166>Sep 12 14:57:00 X.X.X.X Spantree[4]Topology Change: RECEIVED on SID = 0
Port = lag.0.1
on Core 2 there is nothing at the same time.

And when Core 2 shows topology change
<166>Sep 12 14:22:04 X.X.X.X Spantree[4]Topology Change: RECEIVED on SID = 0
Port = lag.0.1
An core 1 was nothing at the same time.

Lag.0.1 is our 2x10G between the core 1 and core 2

This is the Netsight syslog what happens on many stacks:

false Info --- 05/09/2016 16:01:58 X.X.X.X --- --- Event --- X.X.X.X dot1s_sm.c(3875) 6017223 %% Setting Port(1) Role: ROLE_DESIGNATED | STP Port(1) | Int Cost(2000000) | Ext Cost(2000000)
false Info --- 05/09/2016 16:01:58 X.X.X.X --- --- Event --- X.X.X.X dot1s_ih.c(1365) 6017222 %% Setting Port(1) instance(0) State: FORWARDING
false Info --- 05/09/2016 16:01:58 X.X.X.X --- --- Event --- X.X.X.X dot1s_ih.c(1302) 6017221 %% Setting Port(1) instance(0) State: LEARNING
false Info --- 05/09/2016 16:01:58 X.X.X.X --- --- Event --- X.X.X.X dot1s_ih.c(1423) 6017220 %% Setting Port(1) instance(0) State: DISCARDING
false Info --- 05/09/2016 16:01:58 X.X.X.X --- --- Event --- X.X.X.X dot1s_txrx.c(450) 6017219 %% dot1sMstpTx(): CIST Role Disabled
false Info --- 05/09/2016 16:01:58 X.X.X.X --- --- Event --- X.X.X.X dot1s_ih.c(1423) 6017218 %% Setting Port(1) instance(4095) State: DISCARDING
false Info --- 05/09/2016 16:01:56 X.X.X.X --- --- Event --- X.X.X.X dot1s_ih.c(1423) 6017217 %% Setting Port(1) instance(0) State: DISCARDING
false Info --- 05/09/2016 16:01:56 X.X.X.X --- --- Event --- X.X.X.X dot1s_txrx.c(450) 6017216 %% dot1sMstpTx(): CIST Role Disabled

Is there any possibility to find out if a gbic has a malfunction?

Thanks a lot

Adam

[Daniel_Coughlin]

Adam,

The articles Erik pointed out should help. If you need more assistance give us a call at the GTAC.

[Erik_Auerswald]

Hi Adam,

the GTAC Knowledge site has a few articles regarding STP topology change issues:

• How to troubleshoot spanning tree topology changes on SecureStack, N-Series and S-Series
• S-Series showing a lot of topology changes in the Netsight
• SpanningTree Topology Changes Seen From Downstream Device

Perhaps one of those can help you identifying the device causing topolgy changes.

HTH,
Erik

[Mel78__CISSP__E]

I am surpris why stp or rstp still in used if u use summitstack or bd switches... The reason why stp or rstp is disable by default. All switch to switch link should be IEEE 802.1Q. No daisy chain. To prevent looping, u should use elrp. To load share, u should use IEEE 802.3ad...