09-22-2012 11:47 AM - edited 03-07-2019 09:02 AM
I am trying to intergrate Cisco switches into to a Enterasys MST network in the lab.
I can match the region names and change the ROOT between all switches for MST 0 with no problem but not for any other instance other than 0!
For the other instances (11 and 12) the Enterasys kit see's it self as the root as does the primary Cisco switch!
I have changed priorities on numerous switches to try and see if I can spot a change but can not.
Has anyone seen this before, am I missing a simple command on the Entersys or Cisco kit to get over the vlan 1 (MST0) tag issue or is it something more simple I am just missing?
Thanks in advance for any info.
Solved! Go to Solution.
09-23-2012 12:20 AM
Hello J,
It indeed seems that your Cisco and Enterasys are partitioned into different MSTP regions. From the output of show spanning-tree mst detail:
FastEthernet0/1 of MST11 is boundary forwarding
FastEthernet0/1 of MST12 is boundary forwarding
The region configuration appears to be identical. However, what I do not see is where are the VLANs 1-10,14-4094 mapped on the Enterasys switches. The output of show spantree mstmap shows us the mappings for VLANs 11-13 but I do not see any indication of VLAN mappings into the MSTI 0. Are they certainly mapped to MSTI 0 on Enterasys?
A helpful indication is the configuration digest. This is a MD5 digest of the VLAN-to-instance mapping, and is carried in MST BPDUs. Obviously, it must match between switches in the same region. The Enterasys reports it as:
Configuration Digest:c8:02:17:44:25:20:9e:ea:66:13:94:79:6a:f4:c5:96
Can you please issue the show span mst config digest command on the Catalyst and post the output here? Thanks!
Best regards,
Peter
09-22-2012 02:25 PM
Hello,
This is an interesting problem indeed. It seems as if Cisco and the Enterasys were in different regions. The IST (MSTI 0) is propagated between regions but other instances remain limited to their regions and each of them has its own regional root. This seems to correlate to your findings.
Please check the show spanning-tree command output on Cisco switch connected to the Enterasys and look for any ports described as Bound (boundary) ports. If you see any such ports then that confirms that your Cisco and the Enterasys are in different regions.
Note that for two MSTP switches to be in the same region, all three following configuration elements must match:
Please double check these settings.
Best regards,
Peter
09-22-2012 08:33 PM
Hi Peter
Here is the Enterasys MST configs:
C2(rw)->show spantree mstilist
Configured Multiple Spanning Tree Instances:
11 12
C2(rw)->show spantree mstcfgid
MST Configuration Identifier:
Format Selector: 0
Configuration Name: LKS
Revision Level: 1
Configuration Digest:c8:02:17:44:25:20:9e:ea:66:13:94:79:6a:f4:c5:96
C2(rw)->
C2(rw)->show spantree mstmap
Fid 11 is mapped to Sid 11
Fid 12 is mapped to Sid 12
Fid 13 is mapped to Sid 12
C2(rw)->
C2(rw)->
--------,snip from show config----------
#spantree
set spantree mstcfgid cfgname 'LKS' rev 1
set spantree msti sid 11 create
set spantree msti sid 12 create
set spantree mstmap 11 sid 11
set spantree mstmap 12 sid 12
set spantree mstmap 13 sid 12
set spantree priority 0 0
set spantree priority 0 11
set spantree priority 0 12
!
--------------end----------------
and here is the Cisco 3550 config:
SWITCH_1#sh spanning-tree mst configuration
Name [LKS]
Revision 1
Instance Vlans mapped
-------- ---------------------------------------------------------------------
0 1-10,14-4094
11 11
12 12-13
-------------------------------------------------------------------------------
SWITCH_1#sh spanning-tree mst detail
###### MST00 vlans mapped: 1-10,14-4094
Bridge address 000d.bc43.7780 priority 24576 (24576 sysid 0)
Root address 0001.f45d.ec74 priority 0 (0 sysid 0)
port Fa0/1 path cost 200000
IST master this switch
Operational hello time 2, forward delay 15, max age 20
Configured hello time 2, forward delay 15, max age 20, max hops 20
FastEthernet0/1 of MST00 is root forwarding
Port info port id 128.1 priority 128 cost 200000
Designated root address 0001.f45d.ec74 priority 0 cost 0
Designated ist master address 000d.bc43.7780 priority 24576 cost 0
Designated bridge address 0001.f45d.ec74 priority 0 port id 128.1
Timers: message expires in 5 sec, forward delay 0, forward transitions 1
Bpdus sent 915, received 455
FastEthernet0/2 of MST00 is designated forwarding
Port info port id 128.2 priority 128 cost 200000
Designated root address 0001.f45d.ec74 priority 0 cost 200000
Designated ist master address 000d.bc43.7780 priority 24576 cost 0
Designated bridge address 000d.bc43.7780 priority 24576 port id 128.2
Timers: message expires in 0 sec, forward delay 0, forward transitions 2
Bpdus sent 510, received 10
###### MST11 vlans mapped: 11
Bridge address 000d.bc43.7780 priority 24587 (24576 sysid 11)
Root this switch for MST11
FastEthernet0/1 of MST11 is boundary forwarding
Port info port id 128.1 priority 128 cost 200000
Designated root address 000d.bc43.7780 priority 24587 cost 0
Designated bridge address 000d.bc43.7780 priority 24587 port id 128.1
Timers: message expires in 0 sec, forward delay 0, forward transitions 1
Bpdus (MRecords) sent 917, received 0
FastEthernet0/2 of MST11 is designated forwarding
Port info port id 128.2 priority 128 cost 200000
Designated root address 000d.bc43.7780 priority 24587 cost 0
Designated bridge address 000d.bc43.7780 priority 24587 port id 128.2
Timers: message expires in 0 sec, forward delay 0, forward transitions 1
Bpdus (MRecords) sent 511, received 10
###### MST12 vlans mapped: 12-13
Bridge address 000d.bc43.7780 priority 32780 (32768 sysid 12)
Root this switch for MST12
FastEthernet0/1 of MST12 is boundary forwarding
Port info port id 128.1 priority 128 cost 200000
Designated root address 000d.bc43.7780 priority 32780 cost 0
Designated bridge address 000d.bc43.7780 priority 32780 port id 128.1
Timers: message expires in 0 sec, forward delay 0, forward transitions 1
Bpdus (MRecords) sent 919, received 0
FastEthernet0/2 of MST12 is designated forwarding
Port info port id 128.2 priority 128 cost 200000
Designated root address 000d.bc43.7780 priority 32780 cost 0
Designated bridge address 000d.bc43.7780 priority 32780 port id 128.2
Timers: message expires in 0 sec, forward delay 0, forward transitions 1
Bpdus (MRecords) sent 512, received 10
SWITCH_1#
-----------end-----------------
As I can show here the MST0 0n the 3550 can see .ec74 as the ROOT but not for the other instance even with .ec74 priority set to 0 for all instances. As best I can tell the name, rev and mappings are the same.
Any ideas or help much appreciated.
Thanks
J
09-23-2012 12:20 AM
Hello J,
It indeed seems that your Cisco and Enterasys are partitioned into different MSTP regions. From the output of show spanning-tree mst detail:
FastEthernet0/1 of MST11 is boundary forwarding
FastEthernet0/1 of MST12 is boundary forwarding
The region configuration appears to be identical. However, what I do not see is where are the VLANs 1-10,14-4094 mapped on the Enterasys switches. The output of show spantree mstmap shows us the mappings for VLANs 11-13 but I do not see any indication of VLAN mappings into the MSTI 0. Are they certainly mapped to MSTI 0 on Enterasys?
A helpful indication is the configuration digest. This is a MD5 digest of the VLAN-to-instance mapping, and is carried in MST BPDUs. Obviously, it must match between switches in the same region. The Enterasys reports it as:
Configuration Digest:c8:02:17:44:25:20:9e:ea:66:13:94:79:6a:f4:c5:96
Can you please issue the show span mst config digest command on the Catalyst and post the output here? Thanks!
Best regards,
Peter
09-23-2012 03:49 AM
Hi Peter
Thanks for your help on this. This appears to be a hidden command on the ver of IOS I am running!
As you say the do match on the two Cisco switches which operate fine but not on the Enterasys!
Thanks
J
SWITCH_1#sh spanning-tree mst config digest
Name [LKS]
Revision 1
Instance Vlans mapped
-------- ---------------------------------------------------------------------
0 1-10,14-4094
11 11
12 12-13
-------------------------------------------------------------------------------
Digest FC6C23DB8E234B7F0E34E1CC895BC511
SWITCH_1#
-----------------The other Cisco switch----------------------
SWITCH_2#sh span mst config dige
Name [LKS]
Revision 1
Instance Vlans mapped
-------- ---------------------------------------------------------------------
0 1-10,14-4094
11 11
12 12-13
-------------------------------------------------------------------------------
Digest FC6C23DB8E234B7F0E34E1CC895BC511
SWITCH_2#
09-23-2012 04:17 AM
Hi Peter
Thank you very much for your input.
I upgrade the IOS on the 3550's and can not see the correct root!!
If you had not shown me that command, it made me realise if I was running IOS with hidden commands a upgrade was needed. This is the new ver output:
SWITCH_1#sh spanning-tree mst configuration ?
digest Display MST configuration digest
| Output modifiers
SWITCH_1#sh spanning-tree mst configuration digest
Name [LKS]
Revision 1 Instances configured 3
Digest 0xC802174425209EEA661394796AF4C596
Pre-std Digest 0xFC6C23DB8E234B7F0E34E1CC895BC511
SWITCH_1#
SWITCH_1#sh spanning-tree mst
##### MST0 vlans mapped: 1-10,14-4094
Bridge address 000d.bc43.7780 priority 24576 (24576 sysid 0)
Root address 0001.f45d.ec74 priority 0 (0 sysid 0)
port Fa0/1 path cost 0
Regional Root address 0001.f45d.ec74 priority 0 (0 sysid 0)
internal cost 200000 rem hops 19
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
---------------- ---- --- --------- -------- --------------------------------
Fa0/1 Root FWD 200000 128.1 P2p
Fa0/2 Desg FWD 200000 128.2 P2p
Fa0/3 Desg FWD 200000 128.3 P2p Edge
##### MST11 vlans mapped: 11
Bridge address 000d.bc43.7780 priority 24587 (24576 sysid 11)
Root address 0001.f45d.ec74 priority 11 (0 sysid 11)
port Fa0/1 cost 200000 rem hops 19
Interface Role Sts Cost Prio.Nbr Type
---------------- ---- --- --------- -------- --------------------------------
Fa0/1 Root FWD 200000 128.1 P2p
Fa0/2 Desg FWD 200000 128.2 P2p
##### MST12 vlans mapped: 12-13
Bridge address 000d.bc43.7780 priority 32780 (32768 sysid 12)
Root address 0001.f45d.ec74 priority 12 (0 sysid 12)
port Fa0/1 cost 200000 rem hops 19
Interface Role Sts Cost Prio.Nbr Type
---------------- ---- --- --------- -------- --------------------------------
Fa0/1 Root FWD 200000 128.1 P2p
Fa0/2 Desg FWD 200000 128.2 P2p
SWITCH_1#
------------------------Enteraysy-----------------------------------------
C2(rw)->show spantree mstcfgid
MST Configuration Identifier:
Format Selector: 0
Configuration Name: LKS
Revision Level: 1
Configuration Digest:c8:02:17:44:25:20:9e:ea:66:13:94:79:6a:f4:c5:96
C2(rw)->
-----------------------end--------------------------------------
As you can see I can now see the correct MST operation!
Thanks again Peter for all your help.
Regards
J
09-23-2012 04:23 AM
Hello J,
I am glad you have resolved this issue! The show span mst config digest was a hidden command in older IOS versions but it it an official and documented command now. Even the old 2950 support it - although they also treat it as hidden.
I now know what has happened. Your previous IOS version was running a so-called pre-standard MST version. Cisco started implementing the MST before the 802.1s was finalized. The format of BPDUs between the pre-standard and the official 802.1s is slightly modified. As your Catalyst spoke to the Enterasys using the pre-standard MST, the Enterasys did not entirely understand it, and basing on differing MD5 hash, both switches have declared they're in different regions. You can also see that the older IOS produced just a single MD5 hash while the new IOS produces two hashes - one for the pre-standard MST and the other for the standard 802.1s.
Anyway, thanks for letting me know
Best regards,
Peter
08-30-2018 10:29 AM - edited 08-30-2018 10:31 AM
I'm having this exact same problem. My difference is that I'm using Cisco 9300s and 3850 s that have been added to my Enterasys network. I have the same problem literally as stated above, other than the fact that my configuration digest matches on the enterasys and on The Ciscos. The only differences that I can spot are that, as stated in the previous part of this problem, the default Cisco vlans that are automatically configured are not part of my enterasys network. So when I show the MST map, it does not show those default vlans that are automatically created on Cisco switches. It took me a little while to realize that my enterasys switches had all been misconfigured for mstp, so once I actually got them all configured correctly, they now all talk correctly across all 3 of my instances 0, 10, and 20. In the mean time I had to change the ciscos back to Rstp so they'd work. Once I put the configuration back into the Ciscos and change them from Rapid to MST, Rather than seeing the root bridge as my core S3, they were showing other Cisco switches as the roots for instance 10 and 20, even though the S3 has the lowest priority for each of the instances. I'm totally baffled. Any ideas on how I can find out why the Ciscos are not talking correctly via mstp with the enterasys, even though they have the same revision number, region name, and from what I can tell same VLAN instance mapping, and configuration digest number?
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