MTSP Configuration - HP Procurve <> CISCO Nexus

Oender Uestuen · ‎08-24-2012

Hi all,

at a customer side we have following configuration - redesign ( hp-world managed by me, cisco-world is a Managed-Service so i don't have access.)

I have to two HP-8200zl switches as Core, connected each other with 2 x 10Gps, i use HP-E3800-Stacks as Server-Switches and at the Edge-Side i use HP-E2800-Series, they all are dual-connected, one link to core1, one to core2.

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

| Managed | | Managed |

| Server | | Server |

| Vlan 1 | | Vlan 2 |

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

| |

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

| Managed |

| cisco - nexus - 5548 | (Configured VLANs 1,2)

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

| |

1. Uplink 2. Uplink

| |

|---------| |---------|

| |

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

| CORE1 |-----------LACP-----------| CORE2 | (Configured VLAN 1,2,3, 310,312,340,342)

| HP - 8200zl |-----------LACP-----------| HP - 8200zl |

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

| | | |

| |-- --| |---------| |

| | | |

| 1. Uplink 2. Uplink |

| | | |

| ------------------------ |

| | HP - E3800 - Stack | |

| ------------------------ |

| | |

| ----------- |

| | Clients | |

| ----------- |

| Configured VLAN 1,2,3, 310,312,340,342) |

| |

|------------| |----------|

| |

1. Uplink 1. Uplink

| |

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

| HP - E2800 Edge - SW |

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

|

-----------

| Clients |

-----------

(Configured VLAN 1, 310,340)

To Interoperate with the Cisco-World i have to use a spanning-tree protocol that both worlds support, so i want to use MSTP.

So i began configuring:

core 1:

spanning-tree

spanning-tree config-name "REGION0"

spanning-tree config-revision 1

spanning-tree instance 1 vlan 2 310-339

spanning-tree instance 2 vlan 3 340-369

spanning-tree instance 1 priority 0

spanning-tree instance 2 priority 1

spanning-tree priority 0

core 2:

spanning-tree

spanning-tree config-name "REGION0"

spanning-tree config-revision 1

spanning-tree instance 1 vlan 2 310-339

spanning-tree instance 2 vlan 3 340-369

spanning-tree instance 1 priority 1

spanning-tree instance 2 priority 0

spanning-tree priority 1

Server-Switch / Edge:

spanning-tree

spanning-tree config-name "REGION0"

spanning-tree config-revision 1

spanning-tree instance 1 vlan 2 310-339

spanning-tree instance 2 vlan 3 340-369

I have configured Vlan-Ranges at my Instances, so that i can add new VLANs in this ranges, without to have to change my MSTP Configuration (I hope i am right).

Vlan 1 runs on MSTI0.

I have implemented this config at last weekend and every thing is working, on my Server/Edge-Switches

the Intances show me the right Root/Alternate-Links. Link Failure (simulations) act perfect.

Currently, at the cisco-world is no spanning-tree configured and the second link is deactivated. I want activate the second link, but therefore MSTP has to be configured.

The Uplink-Port is Tagged (Trunk allowed) with VLAN 1,2. I can connect to all Servers at cisco-world from my HP-World.

I have proposed the following config for the nexus (maybe syntax on nexus can differ):

spanning-tree mode mst

spanning-tree extend system-id

!

spanning-tree mst configuration

name REGION0

revision 1

instance 1 vlan 2, 310-339

instance 2 vlan 3, 340-369

Now, the Admin from the Cisco world says, he will not configure all the vlans i have defined, on his switch.

And will only allow VLAN 1,2 on his Uplinks.

1. So, i have to know, does he have to configure all the vlans at the cisco, i thought he has only to define them in his mstp configuration ?

2. What about the uplinks with only allowing vlan 1,2, will this work with my config ?

I hope someone can help me?

P.S.: On my edge-switches i do not need vlan 2,3,312,342 so, i did not configure them. And my Uplink-Ports are only tagged with 310,340 and everthing seems to work. Will this not work with Cisco or is this config not supported by MSTP ?

Thanks for any Support

ouestuen

krahmani323 · ‎08-28-2012

Hello Ouestuen

Thank you for the description provided in your post. About the questions :

1/ You do not have to configure all the vlans in each bridge participating in the MSTP domain.

About VLANs, the only information that needs to match (besides MST configuration NAME & REVISION) is VLAN-to-MSTI mapping. It has to match on every switch that has to be in the same MSTP region.

An easy way to check the configuration is consistent on each side is to compare the digest (MD5 calculated from VLAN-to-MSTI mapping only) on Cisco and HP sides => This digest has to be the same.

(in fact between the Cisco and the HP the entire MST instance-to-VLAN mapping table is not sent in the BPDUs, instead this digest is sent to quickly check).

On the Nexus 5548 the output should be =>

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

N5k-5548P# sh spanning-tree mst configuration

Name [REGION0]

Revision 1 Instances configured 3

Instance Vlans mapped

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

0 1,4-309,370-4094

1 2,310-339

2 3,340-369

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

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

N5k-5548P# sh spanning-tree mst configuration digest

Name [REGION0]

Revision 1 Instances configured 1

Digest 0x1c391c3e7849729fa1cd81436e49c7e6

Pre-std Digest 0x35487b42fe5f032e03bdc69708689578

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

On the HP switch, you can confirm but I think the command is ‘sh spanning-tree mst-config’ (check MST Configuration Digest value).

2/ About point 2, it is not a problem. All the MST information will be exchanged on those trunks as expected. Some elements about this =>

The MST BPDUs are exchanged through MSTI 0 (/ IST). All of the other MSTI information is contained in MST records (M-records), which are encapsulated within MST BPDUs.

The IST always exists on all ports and cannot be deleted, so we can be sure the MSTI information (for all instances will be exchanged) between Cisco and HP.

=> http://www.cisco.com/en/US/docs/switches/datacenter/nexus5000/sw/layer2/513_n1_1/b_Cisco_n5k_layer2_config_gd_rel_513_N1_1_chapter_01100.html#d52281e241a1635

There is just some misconfiguration to avoid (not the case in your scenario).. Those cases are well described here => http://www.cisco.com/en/US/tech/tk389/tk621/technologies_white_paper09186a0080094cfc.shtml#misconfigs

I would just pay attention to the concept of 802.1q trunk with native vlan on the Cisco side vs. the HP tag/untagged concept .

As you mentioned in your P.S, at the time time being it is working well within the HP domain, even if some vlans are not configured on all switches…It should be the same when inserting the Nexus in the MST domain.

A last point => the command “spanning-tree extend system-id” does not longer exists on NxOS platforms; it is enabled by default.

Hope that helps.

Best regards.

Karim

Oender Uestuen · ‎09-11-2012

Hello Karim,

thanks

Best regards

Önder