VLAN Mapppin/Translation Issue

[JLSchooley]

I have been working on setting up connectivity between a host private cloud and our infrastructure.  I need to do VLAN translations from our VLANs to the provider assigned VLANs.  Long story short, the 93180-YC-EX switches that we have don't support VLAN translation without VXLAN configured.  I did get this working without enabling VXLAN, but that isn't a supported configuration, so it wasn't something that we would put in production.  So, based on the TAC case that I opened, they said that the 5600s could do it without having to enable VXLAN.  I now have 5672UPs set up in VPC and having an issue with the VLAN translations.  The network that I inherited has most things on VLAN 1.  As soon as I add the mapping for this, it cause the link to flap.  Working with our provider, they say they are seeing a tagged LACP packet.  So, about every 1 minute and 30 seconds, the link flaps.  If I exclude the VLAN mapping from their VLAN to our VLAN 1, everything works seems to be OK.  I'm working on getting Smart Net on these, but that is still in process.  I have been over the documentation over and over and it seems that this should be supported.  Anyone have any ideas?  Thank you in advanced for any assistance.

Running 7.3.7.N1.1a on the 5672UPs.

Switch 1

interface port-channel2

  description BVU_CDC

  switchport mode trunk

  switchport vlan mapping 1001 1

  switchport vlan mapping 1002 250

  switchport trunk allowed vlan 1,250,1000

  spanning-tree port type edge trunk

  spanning-tree bpdufilter enable

  speed 10000

  vpc 2

interface Ethernet1/17

  description BVU_CDC

  switchport mode trunk

  switchport vlan mapping 1001 1

  switchport vlan mapping 1002 250

  switchport trunk allowed vlan 1,250,1000

  channel-group 2 mode active

  no shutdown

Switch 2

interface port-channel2

  description BVU_CDC

  switchport mode trunk

  switchport vlan mapping 1001 1

  switchport vlan mapping 1002 250

  switchport trunk allowed vlan 1,250,1000

  spanning-tree port type edge trunk

  spanning-tree bpdufilter enable

  speed 10000

  vpc 2

interface Ethernet1/17

  description BVU_CDC

  switchport mode trunk

  switchport vlan mapping 1001 1

  switchport vlan mapping 1002 250

  switchport trunk allowed vlan 1,250,1000

  channel-group 2 mode active

  no shutdown

[Sergiu.Daniluk · Accepted solution]

Hello,

Have you tried changing the native vlan on the trunk to something else other then vlan 1?

Regards,

Sergiu

[JLSchooley]

Sergiu,

I tried changing the native VLAN and that seems to have resolved the port-channel link from flapping.  Going to test it in a VPC configuration today.  Looks promising. 

[Sergiu.Daniluk]

Hi @JLSchooley 

Glad to hear that the flapping stopped. I believe the reason for the issue is due to the combination of having:

• vlan 1 as native vlan on your port-channel (default config)
• translation of vlan 1 <-> 1001.

Could be possible that vlan mapping caused the packets to be tagged.

There is also a limitation in the cfg guide about native vlan:

• Do not configure translation of ingress native VLAN traffic on an 802.1Q trunk. The 802.1Q native VLAN traffic is untagged and cannot be recognized for translation. However, you can translate traffic from other VLANs to the native VLAN of an 802.1Q trunk.

Ref: https://www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus5600/sw/layer2/7x/b_5600_Layer2_Config_7x/b_6k_Layer2_Config_7x_chapter_010.html#con_1273512 

Stay safe,

Sergiu

[paul driver]

Hello

---

@JLSchooley wrote:

  Working with our provider, they say they are seeing a tagged LACP packet.  So, about every 1 minute and 30 seconds, the link flaps. As soon as I add the mapping for this, it cause the link to flap.  Working with our provider, they say they are seeing a tagged LACP packet.  So, about every 1 minute and 30 seconds, the link flaps.  If I exclude the VLAN mapping from their VLAN to our VLAN 1, everything works seems to be OK.  

---

Why are you performing the mapping, My understanding is the SP does this, You just need to make sure the your vlans are allowed on the trunk and they relate to what the SP are mapping on.

[JLSchooley]

Paul,

You and me both on the SP doing the VLAN translations.  Unfortunately I being told that they do not do VLAN translations.  I'm testing changing the native VLAN further today.  I have my fingers crossed that this will be the end of my VLAN translation fiasco.