Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 
Announcements

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. And see here for current known issues.

New Member

EoMPLS with different vlans at the ends

Hi guys,

It's possible configure different vlan between CE1-PE1 and CE2-PE2? x example:

CE ip=10.0.0.1 (vlan 5) === PE --MPLS--PE== (vlan 10) ip= 10.0.0.2 CE

It's correct? or exist problem with the configuration?, currently i'm simulating with dynamips and work fine.

Please could be validate the scenario?

Thx in advance!.

10 REPLIES
New Member

Re: EoMPLS with different vlans at the ends

Hi Henrry,

EoMPLS can run in two modes- Ethernet Port mode or Ethernet VLAN mode.

In Ethernet VLAN mode, the VLAN ID is re-written either on ingress PE or egress PE. Hence, the VLAN IDs do not have to match on each side.

However, when you run EoMPLS in Port mode, the whole trunk is carried across the MPLS network and hence VLAN IDs should match.

You can view the type of mode by doing

show mpls l2transport vc command.

HTH.

Amit.

Cisco Employee

EoMPLS with different vlans at the ends

What about using QinQ over EoMPLS.  Can the "outside" vlan tag be re-written from ingress to egress?  (I'd prefer to leave the "inside" Q-tag along.)

Cisco Employee

EoMPLS with different vlans at the ends

This should be possible

1. in an effeciant and scalable manner With the EVC frame work.

https://supportforums.cisco.com/docs/DOC-21299

2.Stacked VLAN processing (The inner tag cannot be changed in this method)

http://www.cisco.com/en/US/docs/ios/12_0s/feature/guide/qinq.html

Check the restrictions section in the above link.

When you configure an EoMPLS tunnel on stacked  VLAN subinterfaces, the SP-VLAN ID is removed from the frame at the  ingress interface. The remote PE router will add (if required) the  SP-VLAN ID configured on its egress subinterface before forwarding the  frame.

examples

-------

Router(config)# interface gigabitethernet3/0.3

Router(config-subif)# encapsulation dot1q 50 second-dot1q any

Router(config-subif)# xconnect 4.4.4.4 200 encapsulation mpls

Hope this helps.

Regards

Ashish

Hall of Fame Super Silver

Re: EoMPLS with different vlans at the ends

Hello Henrry,

this is possible with the so called vlan-id rewrite feature.

It should be possible with the appropriate hardware in current IOS release of cisco 12000 or other platforms like C7600

Have a nice week

Hope to help

Giuseppe

New Member

Re: EoMPLS with different vlans at the ends

No problem running this in C7200 as well.

But be aware if connecting switches in both ends and running STP across preudowire. Will not work. In your scenario switch in vlan 10 would recieve BPDU containing vlan 5 information. Following an err-disabled situation.

Reason for this is that vlan rewrite feature will rewrite header only, not content of BPDU or other control packets

Fix: No STP or BPDU filter or no switch connected at PE

Jon

New Member

Re: EoMPLS with different vlans at the ends

Hi Guys,

For Your Information

We have found the next Bug:

CSCsz14262


In the plataform:

GSR12k  Software release: 12.0(32)SY2


Symptom:
Unable to configure rate-lmit in GE subinterfaces.
Conditions:
GSR running 12.0(32)SY2 with xconnect configured in the subinterface.

Silver

Re: EoMPLS with different vlans at the ends

Hi Henrry

The questione asked is very good. Becuase everytime we think that the vlan should be unique in the MPLS cloud while providing EoMPLS services.But the vlans might be different not the vcid. VCID should be unique through the cloud. When the traffic frded by CE1 over vlan 5 and when the frame comes at PE at that time the vlan tag is removed and vcid comes in picture. So you can use the different vlans but vcid should be unique between the PEs.

regards

shivlu jain

New Member

Re: EoMPLS with different vlans at the ends

Hi,

Is there any command in Cisco to disable VLAN tag rewrite for EoMPLS?

I want to see how PE devices communicate in case the VLAN IDs do not match. According to RFC, they use the "Interface Parameters value 0x16" of PW FEC TLV to order the correct VLAN ID.

Please assist.

Amit.

Cisco Employee

Re: EoMPLS with different vlans at the ends

Hi Amit,

There is no such command.

This optional parameter will be used only when a PE doesn't support VLAN ID rewrite at disposition. It also implies the other PE support VLAN ID rewrite at imposition.

If you want to see it in action, old E2 LC for GSR doesn't support VLAN ID rewrite at disposition. Use an E3 or E5 LC on the other PE.

HTH

Laurent.

New Member

Re: EoMPLS with different vlans at the ends

if your mpls cloud is 7600 with ES+ cards

you can use

service instance 10 ethernet

encapsulation dotq1 10

rewrite ingress tag translate 1-to-1 dot1q 5

xconnect 4.4.4.4 encapsulation mpls

ASR 9k

interface GigabitEthernet0/0/0/0/3.10 l2transport 
encapsulation dot1q 10

 rewrite ingress tag translate 1-to-1 dot1q 5 symmetric

Regards

Jude

2227
Views
3
Helpful
10
Replies