Spanning Tree Problem

[Beero]

Hello, I have a Spanning Tree problem is a site.
The topology is as follows:
- 2 * procurve 8200 Core switches (VRRP), connected to them are multiple switch stacks (2 * A-5120 switches per stack), 2 uplinks going from each stack, one to each Core.

-MSTP is used with 2 instances.

-One instance includes the odd Vlan's and to be sent though 1 uplink (to core 1),
and the other instance includes the even Vlan's and  to be sent through the second uplink (to core 2).

*Problem is all the traffic from both instances is being sent through one of the uplinks (it is forwarding in both instances)
and the second uplink is discarding in both instances.

What do u recommend checking, and if any configuration files needed, I'll upload them.

Thanks,

[Peter_Debruyne]

Hi,

for mstp, the region info has to be identical between all devices.

Check on the

procurve: show span mst-config

comware: dis stp region

Best regards,Peter

[Beero]

Thanks for your reply Peter,
But here are the config answering what you suggested

ProCurve:

show spanning-tree mst-config

MST Configuration Identifier Information

MST Configuration Name : mstp-vrrp
MST Configuration Revision : 1
MST Configuration Digest : 0xE8A800D8B5070FD0FFDF60961CBF6F51

IST Mapped VLANs : 1,3-15,49-237,240-4094

Instance ID        Mapped VLANs
-----------         ---------------------------------------------------------
1                         17,19,21,23,25,27,29,31,33,35,37,39,41,43,45,47
2                          2,16,18,20,22,24,26,28,30,32,34,36,38,40,42,44,46,48,
                             238,239

A-5120:

stp region-configuration
region-name "mstp-vrrp"
revision-level 1
instance 1 vlan 3 17 19 21 23 25 27 29 31 33
instance 1 vlan 35 37 39 41 43 45 47
instance 2 vlan 2 16 18 20 22 24 26 28 30 32
instance 2 vlan 34 36 38 40 42 44 46 48 62 238 to 239

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

i noticed vlan 3 and 62 is missing in the first config ( i will fix it asap ) but could that be the cause of the problem ?!
I also notied that all the traffic sent through one of the uplinks is considered to be instance 0 traffic, so basically only STP is working and the mulitple instances are being ignored for some reason.

thanks,

[Peter_Debruyne]

Hi,

when the MSTP region config is not matching, MSTP will revert to basic RSTP, so then it is normal behavior to see all traffic through 1 link.

This is why you must verify the region configs on all devices...

Best regards,Peter.

[Beero]

Thanks for your reply Peter,

So basically I have to make sure all the switches included in the MSTP must be matched in the config, and I will as soon as possible.
But does the config I posted in the earlier post (for one core and one edge switch)  look healthy enough assuming I synch the Vlan-Instance mappings or is there any command missing ?

Thanks again,
Regards.

[Peter_Debruyne]

no, assuming you fix the instance/vlan mapping it is ok.

Do not forget on comware to run the "active region-configuration" command to make the change really active (required after each config change of any of the region settings).

Verify configs with show/display commands listed in first post,

best regards,Peter

[Richard Litchfield]

Intelligent Management Centre (IMC) shows STP/MSTP details in graphical form. It is very helpful when troublehooting these types of issues where an error or omission can result in an unexpected outcome.

You can download a free 60 day trial of IMC from http://hp.com/networking/imctrial

[Beero · Accepted solution]

Thanks all for your help But the real probelm was as follows:

In HP Procurve Switches ( Core 1 and Core 2), in the configuration if you put "mstp-vrrp"   then the name will be read as  mstp-vrrp

However in the H3C Switch ( 5120 switch), in the configuration if you put "mstp-vrrp"   then the double quote will be kept and the name will be read as : “mstp-vrrp”

[Peter_Debruyne]

Thanks for the update, this is a tricky config issue indeed !