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New Member

Dell STP and Cisco Rapid-PVST+ interoperabillity

Referencing to this doc:

https://supportforums.cisco.com/docs/DOC-16177

which was very helpful, I noticed that I'm getting this error message:

%SW_MATM-4-MACFLAP_NOTIF: Host d067.e5cc.2e49 in vlan 1 is flapping between port Po11 and port Po12

I have Dell PC6248 connected to C3560 with two port channels. In fact, I have two Dell switches in a stack. As document describes, I configured MST on both switches and that resolved slow convergence of network, but above message now appears.

That MAC address is no host:


Cisco switch
Dell switch

Cisco switch:

Router_Switch#sh mac address-table

          Mac Address Table

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

Vlan    Mac Address       Type        Ports

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

All    0100.0ccc.cccc    STATIC      CPU

All    0100.0ccc.cccd    STATIC      CPU

All    0180.c200.0000    STATIC      CPU

All    0180.c200.0001    STATIC      CPU

All    0180.c200.0002    STATIC      CPU

All    0180.c200.0003    STATIC      CPU

All    0180.c200.0004    STATIC      CPU

All    0180.c200.0005    STATIC      CPU

All    0180.c200.0006    STATIC      CPU

All    0180.c200.0007    STATIC      CPU

All    0180.c200.0008    STATIC      CPU

All    0180.c200.0009    STATIC      CPU

All    0180.c200.000a    STATIC      CPU

All    0180.c200.000b    STATIC      CPU

All    0180.c200.000c    STATIC      CPU

All    0180.c200.000d    STATIC      CPU

All    0180.c200.000e    STATIC      CPU

All    0180.c200.000f    STATIC      CPU

All    0180.c200.0010    STATIC      CPU

All    ffff.ffff.ffff    STATIC      CPU

   1    d067.e5cc.2e49    DYNAMIC     Po11

255    d067.e5cc.2e47    DYNAMIC     Po11

Total Mac Addresses for this criterion: 22

WSS_Dell_PC6248#show bridge address-table

Aging time is 300 Sec

  Vlan        Mac Address       Port          Type  

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

1        04C5.A464.301F        ch1        Dynamic             

1        04C5.A464.3025        ch2        Dynamic             

1        04C5.A464.3028        ch1        Dynamic             

255      04C5.A464.3045        ch1        Dynamic             

255      D067.E5CC.2E47        cpu        Management          

Total MAC Addresses in use:5


VLAN 255 is mgmt vlan. I didn't get that message before using mst.

Configuration of trunk ports on Dell:

!

interface port-channel 1

description 'TRUNK_3560_1'

switchport mode general

switchport general allowed vlan add 10,255 tagged

exit

!

What seems to be the problem here?

Everyone's tags (5)
1 ACCEPTED SOLUTION

Accepted Solutions

Re: Dell STP and Cisco Rapid-PVST+ interoperabillity

Cisco

##### MST0    vlans mapped:   1-4094

Dell

###### MST 0 Vlan Mapped:   1, 10, 20, 255

MSTP BPDUs contain a digest of the VLANs-to-instance mapping table and this digests have to match on all switches within the Region (in addition with the revision number and the name). You can check the digest on the Cisco switch with "show spanning-tree mst configuration digest", I guess there is also a command to show it available for the Dell.

I'm not sure if this is really an issue in your scenario because the Dell has accepted the Cisco as the root bridge.

[]EDIT:

WSS_Dell_PC6248#show spanning-tree mst-configuration

Name: D0-67-E5-CC-2E-47

Revision: 0

Names and Revisions also have to match.

HTH

Rolf

4 REPLIES
Silver

Dell STP and Cisco Rapid-PVST+ interoperabillity

show spanning-tree mst 0
show etherchannel summary

Check the same on Dell side.

Check the port channel cabling to make sure the member links form the same pairs on both sides.
New Member

Dell STP and Cisco Rapid-PVST+ interoperabillity

CISCO 3560:

Router_Switch#show spanning-tree mst 0

##### MST0    vlans mapped:   1-4094

Bridge        address 04c5.a464.3000  priority      32768 (32768 sysid 0)

Root          this switch for the CIST

Operational   hello time 2 , forward delay 15, max age 20, txholdcount 6

Configured    hello time 2 , forward delay 15, max age 20, max hops    20

Interface        Role Sts Cost      Prio.Nbr Type

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

Fa0/25           Desg FWD 200000    128.29   P2p

Po11             Desg FWD 100000    128.136  P2p

Po12             Desg FWD 100000    128.144  P2p

Router_Switch#show etherchannel summary

Flags:  D - down        P - bundled in port-channel

        I - stand-alone s - suspended

        H - Hot-standby (LACP only)

        R - Layer3      S - Layer2

        U - in use      f - failed to allocate aggregator

        M - not in use, minimum links not met

        u - unsuitable for bundling

        w - waiting to be aggregated

        d - default port

Number of channel-groups in use: 2

Number of aggregators:           2

Group  Port-channel  Protocol    Ports

------+-------------+-----------+-----------------------------------------------

11     Po11(SU)         -        Fa0/33(P)   Fa0/35(P)  

12     Po12(SU)         -        Fa0/27(P)   Fa0/36(P)

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

DELL:

WSS_Dell_PC6248#show interfaces port-channel

Channel   Ports                         Hash Algorithm Type

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

ch1       Active: 1/g48, 2/g48          3

ch2       Active: 1/g47, 2/g47          3

(output omited)

WSS_Dell_PC6248#show spanning-tree mst-configuration

Name: D0-67-E5-CC-2E-47

Revision: 0

Instance    Vlan Mapped

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

0          1, 10, 20, 255

WSS_Dell_PC6248#show spanning-tree        

Spanning tree Enabled  BPDU flooding Disabled Portfast BPDU filtering  Disabled mode mstp

CST Regional Root:        A0:00:D0:67:E5:CC:2E:47

Regional Root Path Cost:  0

###### MST 0 Vlan Mapped:   1, 10, 20, 255

ROOT ID

              Address         04:C5:A4:64:30:00

              Path Cost       100000

              Root Port      ch2   

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

Bridge ID

              Priority        40960

              Address         D0:67:E5:CC:2E:47

              Hello Time 2 Sec Max Age 20 sec Forward Delay 15 sec TxHoldCount 6 sec

(output omited)

  1/g47   Enabled  128.47            0   FWD  Disb      No      No 

1/g48   Enabled  128.48            0   FWD  Disb      No      No 

(output omited)

ch1     Enabled   96.626      100000   DSC  Altn      No      No 

ch2     Enabled   96.627      100000   FWD  Root      No      No 

(output omited)

Re: Dell STP and Cisco Rapid-PVST+ interoperabillity

Cisco

##### MST0    vlans mapped:   1-4094

Dell

###### MST 0 Vlan Mapped:   1, 10, 20, 255

MSTP BPDUs contain a digest of the VLANs-to-instance mapping table and this digests have to match on all switches within the Region (in addition with the revision number and the name). You can check the digest on the Cisco switch with "show spanning-tree mst configuration digest", I guess there is also a command to show it available for the Dell.

I'm not sure if this is really an issue in your scenario because the Dell has accepted the Cisco as the root bridge.

[]EDIT:

WSS_Dell_PC6248#show spanning-tree mst-configuration

Name: D0-67-E5-CC-2E-47

Revision: 0

Names and Revisions also have to match.

HTH

Rolf

New Member

Dell STP and Cisco Rapid-PVST+ interoperabillity

Today I started scenario again and it didn't show the flapping message and I even didn't configure mst instances to be same on both switches. However, just in case I will configure instances to be equal on both sides. Thanks.

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