spanning tree problem

Muhammed AKYUZ · ‎11-22-2011

Hi,

there is a iscsi storage device stat is connected to g0/39 and G0/40 switch which is running rapid PVST.

port configuration is below.

Even though there is bpdu guard, port is becoming designated. What should be the problem?

!

interface GigabitEthernet1/39

description SVCGM_A(2)

switchport access vlan 111

switchport mode access

spanning-tree portfast

spanning-tree bpduguard enable

end

1#sh run int g1/40

Building configuration...

Current configuration : 169 bytes

!

interface GigabitEthernet1/40

description SVCGM_C(2)

switchport access vlan 111

switchport mode access

spanning-tree portfast

spanning-tree bpduguard enable

end

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

447322: 4y5w: RSTP(111): initializing port Gi1/39

447323: 4y5w: RSTP(111): Gi1/39 is now designated

447324: 4y5w: RSTP(111): initializing port Gi1/39

447325: 4y5w: RSTP(111): Gi1/39 is now designated

447326: 4y5w: RSTP(111): initializing port Gi1/39

447327: 4y5w: RSTP(111): Gi1/39 is now designated

447328: 4y5w: RSTP(111): initializing port Gi1/39

447329: 4y5w: RSTP(111): Gi1/39 is now designated

447330: 4y5w: RSTP(111): initializing port Gi1/39

447331: 4y5w: RSTP(111): Gi1/39 is now designated

447332: 4y5w: RSTP(111): initializing port Gi1/39

447333: 4y5w: RSTP(111): Gi1/39 is now designated

447334: 4y5w: RSTP(111): initializing port Gi1/39

447335: 4y5w: RSTP(111): Gi1/39 is now designated

447336: 4y5w: RSTP(111): initializing port Gi1/39

447337: 4y5w: RSTP(111): Gi1/39 is now designated

447338: 4y5w: RSTP(111): initializing port Gi1/39

447339: 4y5w: RSTP(111): Gi1/39 is now designated

447340: 4y5w: RSTP(111): initializing port Gi1/39

447341: 4y5w: RSTP(111): Gi1/39 is now designated

447342: 4y5w: RSTP(111): initializing port Gi1/39

447343: 4y5w: RSTP(111): Gi1/39 is now designated

447344: 4y5w: RSTP(111): initializing port Gi1/39

447345: 4y5w: RSTP(111): Gi1/39 is now designated

447346: 4y5w: RSTP(111): initializing port Gi1/40

447347: 4y5w: RSTP(111): Gi1/40 is now designated

447348: 4y5w: RSTP(111): initializing port Gi1/40

447349: 4y5w: RSTP(111): Gi1/40 is now designated

447350: 4y5w: RSTP(111): initializing port Gi1/40

447351: 4y5w: RSTP(111): Gi1/40 is now designated

447352: 4y5w: RSTP(111): initializing port Gi1/40

447353: 4y5w: RSTP(111): Gi1/40 is now designated

447354: 4y5w: RSTP(111): initializing port Gi1/40

447355: 4y5w: RSTP(111): Gi1/40 is now designated

447356: 4y5w: RSTP(111): initializing port Gi1/40

447357: 4y5w: RSTP(111): Gi1/40 is now designated

447358: 4y5w: RSTP(111): initializing port Gi1/40

447359: 4y5w: RSTP(111): Gi1/40 is now designated

447360: 4y5w: RSTP(111): initializing port Gi1/40

447361: 4y5w: RSTP(111): Gi1/40 is now designated

447362: 4y5w: RSTP(111): initializing port Gi1/40

447363: 4y5w: RSTP(111): Gi1/40 is now designated

447364: 4y5w: RSTP(111): initializing port Gi1/40

447365: 4y5w: RSTP(111): Gi1/40 is now designated

447366: 4y5w: RSTP(111): initializing port Gi1/40

447367: 4y5w: RSTP(111): Gi1/40 is now designated

447368: 4y5w: RSTP(111): initializing port Gi1/40

447369: 4y5w: RSTP(111): Gi1/40 is now designated

447370: 4y5w: RSTP(111): initializing port Gi1/40

447371: 4y5w: RSTP(111): Gi1/40 is now designated

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

SWITCH#sh spanning-tree vlan 111

VLAN0111

Spanning tree enabled protocol rstp

Root ID Priority 8192

Address 001c.0f66.6c6f

Cost 2

Port 49 (TenGigabitEthernet1/49)

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

Bridge ID Priority 32879 (priority 32768 sys-id-ext 111)

Address 001b.d496.d540

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

Aging Time 300

Interface Role Sts Cost Prio.Nbr Type

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

Gi1/7 Desg FWD 4 128.7 P2p

Gi1/10 Desg FWD 4 128.10 P2p

Gi1/12 Desg FWD 4 128.12 P2p

Gi1/13 Desg FWD 4 128.13 P2p

Gi1/23 Desg FWD 4 128.23 P2p Edge

Gi1/30 Desg FWD 4 128.30 P2p

Gi1/38 Desg FWD 4 128.38 P2p

Gi1/39 Desg FWD 4 128.39 P2p Edge

Gi1/40 Desg FWD 4 128.40 P2p Edge

Te1/49 Root FWD 2 128.49 P2p

Te1/50 Altn BLK 2 128.50 P2p

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

SWITCH#sh ver

Cisco IOS Software, Catalyst 4500 L3 Switch Software (cat4500-IPBASEK9-M), Version 12.2(31)SGA1, RELEASE SOFTWARE (fc3)

Technical Support: http://www.cisco.com/techsupport

Compiled Fri 26-Jan-07 14:35 by kellythw

Image text-base: 0x10000000, data-base: 0x115C5630

ROM: 12.2(31r)SGA

Pod Revision 0, Force Revision 34, Gill Revision 20

smitesh kharecha · ‎11-22-2011

Seems like some bug.

Can you reload the switch and check whether it is still becoming designated port ?

Regards,

Smitesh

Muhammed AKYUZ · ‎11-22-2011

we are not able to reload the swtich. it is in production. Do you now any bug id?

JohnTylerPearce · ‎11-22-2011

Is this log continuous? Do you keep getting these messags non stop?

The ports 1/39 and 1/40 should always be Designated Ports, since they both connect to an end device.

Now if for some reason, the root port Te1/49 lost connectivity to the root switch, it would use the alternate port

almost immeidately, which should cause RPVST to start recalculating.

Edwin Summers · ‎11-22-2011

No problem here, unless you're experiencing another issue or outage.

BPDUguard simply disables the port if the port receives BPDUs, such as if a switch or other STP-enabled device is connected to it. The port itself will still participate in spanning-tree, and will be designated for the segments as you are seeing. In addition, the ports are showing P2P Edge as they should.

The ports will not be root ports, as that would indicate the root bridge can be reached through them. This should not be the case if you've planned to configure BPDU guard on the ports.

The ports also should not be disabled, as that would prevent traffic from your storage device from being forwarded.

Not sure if I understand what problem you're experiencing. What are you expecting to see here?

Off-topic: Are ports Te1/49 and Te1/50 connected to the same upstream switch?