vlan is allowed in topology 1 but getting message related to vlan down for topology 2 + nexus

[kmothukuri]

Hi all ,

Nexus 7ks are connected to nexus 5ks as per the diagram.

nexus 7ks -- Prod VDC -- Topology 1 and Non prod VDC ---> Topology 2.

Fabricpath is configured between nexus 7ks and nexus 56128.

Whenever we are creating new vlan 3020 in Prod VDC under topology 1 , we are getting below messages after enabling below commands on 56128 switches.

why are we seeing below message even though Eth1/x is part of topology 1 only ..We have separate LAN uplink from 56128 to nexus 7ks which are part of topology 2 ONLY.

%L3VM-5-FP_TPG_INTF_DOWN: Interface Ethernet1/x down in fabricpath topology 2 - All VLAN down on interface

interface Ethernet1/x
description 56128P to Nexus 7ks PROD VDC
switchport mode fabricpath
fabricpath topology-member 1

nexus7ks

----------

fabricpath topology 1

member vlan 3020

vlan 3020

mode fabricpath

int vlan 3020

ip address x.x.x.x/24

no shut

nexus 5ks'

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

fabricpath topology 1

member vlan 3020

vlan 3020

mode fabricpath

[Sergiu.Daniluk]

Hi,

Looks like a cosmetic log. Did you experienced any problems for either of the FP topologies?

Everything looks ok in fp topology output?

switch# show fabricpath topology vlan
switch# show fabricpath isis topology summary

Also, do you get the error log if you configure first the vlan as FP vlan and then allowing it in the topology 1?

Regards,

Sergiu

[kmothukuri]

Hi Sergiu ,

Yes everything looks fine from Fabricpath point of view and newly created vlan is also working fine .

My main concern is that why are we getting all vlan down related to topology 2 on the interface eth 1/x where we have allowed only topology 1 vlans.

Do you have any document in handy  where we have steps to be followed in order to configure new vlan under particular topology ..

As per the cisco best practice document , we could see below statement. page number 14 in white_paper_c07 document.

This recommendation is applicable only to mode fabricpath VLANs, not to mode CE VLANs.

Note that when a new mode fabricpath VLAN is configured, it is automatically assigned to the default Topology 0. If you need to a newly created VLAN to belong to specific topology from the start, you should assign this VLAN to the desired topology prior to configuring it with the mode fabricpath command.

But Page number 5 and 6 of fp_n5600_forwarding document says

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

Setting the VLAN Mode to FabricPath or CE

The default VLAN mode is CE.

You designate those VLANs that you want to carry FabricPath traffic on the network by configuring

them as FabricPath VLANs.

BEFORE YOU BEGIN

Ensure that you have created the VLANs.

SUMMARY STEPS

1. configure terminal

2. vlan vlan-id

3. mode [ce | fabricpath]

4. exit

5. (Optional) show fabricpath topology vlans [active]

6. (Optional) copy running-config startup-config

and then

Mapping FabricPath VLANs to a Topology

The default VLAN mode is CE.

You designate those VLANs that you want to carry FabricPath traffic on the network by configuring

them as FabricPath VLANs. By default, all FabricPath VLANs belong to default topology 0. Also

FabricPath VLANs can be a member of only one topology.

BEFORE YOU BEGIN

Ensure that you have created the VLANs.

SUMMARY STEPS

1. configure terminal

2. fabricpath topology topology-number

3. member vlan vlan-id

4. (Optional) show fabricpath topology vlans [active]

5. (Optional) copy running-config startup-config

What is the correct order to place A vlan in Fabric and and also in topology 1 or 2 ?

Fabricpath toplogy 1

member vlan  2001

Vlan 2001

mode fabricpath

OR

Vlan 2001

mode fabricpath

Fabricpath toplogy 1

member vlan  2001

[Sergiu.Daniluk · Accepted solution]

Hi,

Just to confirm, do you have 3 topologies configured: default topology (topology 0), topology 1 (prod) and topology 2 (non-prod)? Because on Nexus 5/6k it's supported maximum 2 topologies:

Note Cisco Nexus devices supports two Fabricpath topologies, the default or base topology (topology 0), and another optional topology (for example, topology 1).

Reference: https://www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus5600/sw/fabricpath/7x/fp_n5600_config/fp_n5600_switching.html 

It might be something related to this.

Regarding the configuration steps, I do not believe there is a restriction to allocate the vlan to a topology before changing to FP. This is only needed, as the whitepaper says, if you want that vlan to be part of a different topology from the start.

However, I believe this is how I would configure it:

# 1. Configure the vlan in CE
conf t
  vlan 2001

# 2. Add vlan to topology
  fabricpath toplogy 1
    member vlan 2001

# 3. Change the mod to FP
  vlan 2001
    mode fabricpath

Regards,

Sergiu

[kmothukuri]

Hi Sergiu ,

Thank you for the steps provided while placing any vlan in a specific topology.

You have mentioned that as per the Cisco document , number of fabricpath topologies supported on 5600 are only TWO , default one ie topology 0 and another topology .

In My setup we are using 56128P switches where we have topology 1 and 2 are running along with default one ie topology 0.

We have to have fabricpath license on the switch where we are going to configure fabricpath .

Can you please also confirm whether number of topologies supported on nexus , will it depend on License , which we purchase OR is it specific to platform model.

Many Thanks for the quick reply.

[Sergiu.Daniluk]

Hello,

ENHANCED_LAYER2_PKG license allows you to enable and run the fabricpath feature.

The number of typologies is directly dependent on the hardware/software. As per documentation (present in scalability guide as well), N5K/6K supports maximum 2 FP typologies.

Have a nice weekend!

Sergiu

[kmothukuri]

Hi Sergiu ,

I have followed steps provided by you and as per cisco recommended  document and I could see vlan down message only on two switches where we have allowed NEW vlan on 16 access switches ie 56128 P in FP - topology 1 .

%L3VM-5-FP_TPG_INTF_DOWN: Interface Ethernet1/50 down in fabricpath topology 2 - All VLAN down on interface

But Int eth 1/50 is part of topology 1 Only .

What I suspect is that above message is dependent on OS of the 56128P.

Still am not sure why are we getting such kind of message even though all vlans under topology 1 and 2 are working fine.

Thanks,

Satish

[Sergiu.Daniluk]

Yep, it might be possible to be a cosmetic defect.

Regards,

Sergiu

[kmothukuri]

Hi sergiu ,

I have one more doubt related to topologies.

We have Three VDCs on nexus7ks example Prod , Non Prod , BE . We have Prod vlans in topology 1 and Non Prod , BE vlans in topology 2.

Suppose if I want to configure new vlan in BE VDC in Topology 2 , do I need to allow it on Non Prod VDC as well under topology 2.

Is there any cisco document where we have VDCs and different topologies configuration example mentioned.

Many Thanks,

Satish