cancel
Showing results for 
Search instead for 
Did you mean: 
cancel
Announcements
Join Customer Connection to register!
719
Views
0
Helpful
10
Replies
hslee
Beginner

cat3550-12G spanning-tree problem

I have a problem on cat3550-12G switch.

I have tested the spanning-tree on cat3550-12G.

But, the stp operation is abnormal.

Two switch SW1 and SW2 are connected with two links.

There is no blocking port on any switch.

Two switch think root bridge itself.

Then, I had captured the BPDU frame.

The destination address of BPDU frames is not 0180c2000000.

The first octet is always different.

IOS : c3550-i5q3l2-mz.121-8.EA1c

10 REPLIES 10
Prashanth Krishnappa
Cisco Employee

This cannot happen. Please check for any misconfigurations. Upgrade to latest 12.1(9)EA1, and if you still see the issue

If I were you, I told as you.

Other people don't believe as you.

First, Also I doubt the configuration as you.

But, the people that have tested cat3550-12G doubt cat3550-12G switch.

Do you see other question on this web about cat3550-12G stp.

This problem is happened already.

If you possible, please test this problem with cat3550-12G.

And then, Let's talk again.

Must be cat3550-12G. not cat3550-12T, other.

The cat3550-12T and cat3550-48G is normal.

Thank you.

I set it up here in the lab and STP is working as it's expected to. My lab switches(both 3550-12G) are running 121-9.EA1c. The switches mostly have default config(assigned all interfaces to VLAN 1).

Switch A

switch-A#sh cdp neighbors

Capability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge

S - Switch, H - Host, I - IGMP, r - Repeater

Device ID Local Intrfce Holdtme Capability Platform Port ID

switch-B Gig 0/12 166 S I WS-C3550-1Gig 0/12

switch-B Gig 0/1 166 S I WS-C3550-1Gig 0/1

switch-A#sh spanning-tree root

Root Hello Max Fwd

Vlan Root ID Cost Time Age Dly Root Port

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

VLAN0001 32769 0005.ddc5.6f00 4 2 20 15 Gi0/1

switch-A#sh spanning-tree vlan 1

VLAN0001

Spanning tree enabled protocol ieee

Root ID Priority 32769

Address 0005.ddc5.6f00

Cost 4

Port 1 (GigabitEthernet0/1)

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

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

Address 0005.ddc5.8900

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

Aging Time 300

Interface Port ID Designated Port ID

Name Prio.Nbr Cost Sts Cost Bridge ID Prio.Nbr

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

Gi0/1 128.1 4 FWD 0 32769 0005.ddc5.6f00 128.1

Gi0/12 128.12 4 BLK 0 32769 0005.ddc5.6f00 128.12

switch-A#

SWITCH B

switch-B#sh cdp neighbors

Capability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge

S - Switch, H - Host, I - IGMP, r - Repeater

Device ID Local Intrfce Holdtme Capability Platform Port ID

switch-A Gig 0/12 168 S I WS-C3550-1Gig 0/12

switch-A Gig 0/1 168 S I WS-C3550-1Gig 0/1

switch-B#sh spanning-tree root

Root Hello Max Fwd

Vlan Root ID Cost Time Age Dly Root Port

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

VLAN0001 32769 0005.ddc5.6f00 0 2 20 15

switch-B#sh spanning-tree vlan 1

VLAN0001

Spanning tree enabled protocol ieee

Root ID Priority 32769

Address 0005.ddc5.6f00

This bridge is the root

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

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

Address 0005.ddc5.6f00

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

Aging Time 300

Interface Port ID Designated Port ID

Name Prio.Nbr Cost Sts Cost Bridge ID Prio.Nbr

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

Gi0/1 128.1 4 FWD 0 32769 0005.ddc5.6f00 128.1

Gi0/12 128.12 4 FWD 0 32769 0005.ddc5.6f00 128.12

switch-B#

I did more research on this and found a bug which is being worked on for a similar issue. Can you please paste output of sh versions from both the switches.

http://www.cisco.com/cgi-bin/bugtool/onebug.pl?bugid=CSCdy34098

Thank you for your help.

I think I need IOS upgrade.

But, I have no switch for lab test.

All switch is working in the field.

Therefore, I will suggest the IOS upgrade from 12.1.8 to 12.1.9EA1c to my customer.

It is strange.

The information of cisco web page recommand IOS 121-8.EA1c for cat3550.

I think it must be corrected.

Thank you very much.

The below is output of show version.

------------------ show version of SW1 ------------------

Cisco Internetwork Operating System Software

IOS (tm) C3550 Software (C3550-I5Q3L2-M), Version 12.1(8)EA1c, RELEASE SOFTWARE

(fc1)

Copyright (c) 1986-2002 by cisco Systems, Inc.

Compiled Fri 15-Feb-02 10:50 by antonino

Image text-base: 0x00003000, data-base: 0x006675E0

ROM: Bootstrap program is C3550 boot loader

sw1 uptime is 40 minutes

System returned to ROM by power-on

System image file is "flash:c3550-i5q3l2-mz.121-8.EA1c/c3550-i5q3l2-mz.121-8.EA1

c.bin"

cisco WS-C3550-12G (PowerPC) processor (revision A0) with 65526K/8192K bytes of

memory.

Processor board ID CAT0625X0AP

Last reset from warm-reset

Bridging software.

Running Layer2/3 Switching Image

Ethernet-controller 1 has 1 Gigabit Ethernet/IEEE 802.3 interface

Ethernet-controller 2 has 1 Gigabit Ethernet/IEEE 802.3 interface

Ethernet-controller 3 has 1 Gigabit Ethernet/IEEE 802.3 interface

Ethernet-controller 4 has 1 Gigabit Ethernet/IEEE 802.3 interface

Ethernet-controller 5 has 1 Gigabit Ethernet/IEEE 802.3 interface

Ethernet-controller 6 has 1 Gigabit Ethernet/IEEE 802.3 interface

Ethernet-controller 7 has 1 Gigabit Ethernet/IEEE 802.3 interface

Ethernet-controller 8 has 1 Gigabit Ethernet/IEEE 802.3 interface

Ethernet-controller 9 has 1 Gigabit Ethernet/IEEE 802.3 interface

Ethernet-controller 10 has 1 Gigabit Ethernet/IEEE 802.3 interface

Ethernet-controller 11 has 1 Gigabit Ethernet/IEEE 802.3 interface

Ethernet-controller 12 has 1 Gigabit Ethernet/IEEE 802.3 interface

12 Gigabit Ethernet/IEEE 802.3 interface(s)

The password-recovery mechanism is enabled.

32K bytes of flash-simulated non-volatile configuration memory.

Base ethernet MAC Address: 00:09:E8:E4:C7:00

Motherboard assembly number: 73-5526-05

Power supply part number: 34-0967-01

Motherboard serial number: CAT06240B08

Power supply serial number: DAB06170HMN

Model revision number: A0

Motherboard revision number: A0

Model number: WS-C3550-12G

System serial number: CAT0625X0AP

Configuration register is 0x10F

------------------ show version of SW2 ------------------

Cisco Internetwork Operating System Software

IOS (tm) C3550 Software (C3550-I5Q3L2-M), Version 12.1(8)EA1c, RELEASE SOFTWARE

(fc1)

Copyright (c) 1986-2002 by cisco Systems, Inc.

Compiled Fri 15-Feb-02 10:50 by antonino

Image text-base: 0x00003000, data-base: 0x006675E0

ROM: Bootstrap program is C3550 boot loader

sw2 uptime is 41 minutes

System returned to ROM by power-on

System image file is "flash:c3550-i5q3l2-mz.121-8.EA1c/c3550-i5q3l2-mz.121-8.EA1

c.bin"

cisco WS-C3550-12G (PowerPC) processor (revision A0) with 65526K/8192K bytes of

memory.

Processor board ID CAT0625X0B0

Last reset from warm-reset

Bridging software.

Running Layer2/3 Switching Image

Ethernet-controller 1 has 1 Gigabit Ethernet/IEEE 802.3 interface

Ethernet-controller 2 has 1 Gigabit Ethernet/IEEE 802.3 interface

Ethernet-controller 3 has 1 Gigabit Ethernet/IEEE 802.3 interface

Ethernet-controller 4 has 1 Gigabit Ethernet/IEEE 802.3 interface

Ethernet-controller 5 has 1 Gigabit Ethernet/IEEE 802.3 interface

Ethernet-controller 6 has 1 Gigabit Ethernet/IEEE 802.3 interface

Ethernet-controller 7 has 1 Gigabit Ethernet/IEEE 802.3 interface

Ethernet-controller 8 has 1 Gigabit Ethernet/IEEE 802.3 interface

Ethernet-controller 9 has 1 Gigabit Ethernet/IEEE 802.3 interface

Ethernet-controller 10 has 1 Gigabit Ethernet/IEEE 802.3 interface

Ethernet-controller 11 has 1 Gigabit Ethernet/IEEE 802.3 interface

Ethernet-controller 12 has 1 Gigabit Ethernet/IEEE 802.3 interface

12 Gigabit Ethernet/IEEE 802.3 interface(s)

The password-recovery mechanism is enabled.

32K bytes of flash-simulated non-volatile configuration memory.

Base ethernet MAC Address: 00:09:E8:E4:D1:80

Motherboard assembly number: 73-5526-05

Power supply part number: 34-0967-01

Motherboard serial number: CAT06240B0R

Power supply serial number: DAB06170HP7

Model revision number: A0

Motherboard revision number: A0

Model number: WS-C3550-12G

System serial number: CAT0625X0B0

Configuration register is 0x10F

=============================================================

This is a similer question.

Aug 1,2002

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

LAN, Switching and Routing

Cat 3550-12G and 2950-24G Spanning Tree Root Problem

j.t.faust@worldnet.att.net - SYSTEMS CONSULTANT, COOPER CAMERON

Aug 1, 2002, 8:13am PST

Have a stack of 2950s with a 3550-12G running current IOSs 12.1(9)EA1d and 12.1.(9)EA1c. The 3550 thinks it's the root bridge and all the 2950s think one of the 2950s is the root. I can connect and ping all the mgmt interfaces for all switches, but not any other device on any port. Any suggestions?

Update.. The 2950s do not hear the BPDUs from the 3550.

Thanks

Ted

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

tstevens - CISCO SYSTEMS, CCIE

Aug 1, 2002, 10:42am PST (1.)

Possible VLAN mismatch? Unidirectional link? Not enough info here to make more than a wild guess.

========================================================

According to upper, cat3550 IOS is 12.1.(9)EA1c .

That is same IOS with you.

So then, 2950-24G has stp problem ??

I am confused.

Please open up the TAC case, for further troubleshooting and narrow down the problem.

Ok

I'll do that.

Thank very much for your help.

Prashanth Krishnappa
Cisco Employee

sbhadrav@cisco.com
Contributor

STP is using the system mac address, you can see this mac address with show version. But, in practice I saw also the case where each interface from this L3 switch had a mac address and the source mac address of the BPDU was the mac of interface transmiting the BPDU but in the BPDU message was contained the system mac.
When a L3 port is transmiting the packet at L3 it will rewrite the L2 header and depends on the platform it can use system mac, or it's own mac address if the system has a different mac address for each interface.

Content for Community-Ad