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EoMPLS point-to-point design

Hello Experts

With EoMPLS point-to-point link can I put a L2 switch facing the Service provider PE routers on both ends, or does it have to be a L3 router? All the cisco documentations seems to show a router.

Reason Im asking is that I have ordered a EoMPLS point to point circuit from my service provider between two cities, and I am not getting an end to end Layer 2 broadcast domain when I connect a switch on each end. The service provider has stated that I need a Router facing back to the service provider on both ends, and a switch wil not work?

I wanted to create a Layer 2 trunk between the two sites and have a flat layer 2 topology between the two ciites.

Is it not possible to have a Layer 2 Ethernet domain via EoMPLS or do I have to use VPLS for this? Please can someone explain this to me and how I can meet my requirements.

Kind Regards

Irfan S.

P.S Diagram is attached of what I am trying to achieve and how we are connecting to the provider.



I'm providing EoMPLS (point-to-point technology) between solutions in my DCs through my core network and in an effect my customers share their L2 VLAN across my core network. With VPLS (point-to-multipoint) they can connect more than two solutions in more than to DCs toghether and again share their single VLAN making my core network acting a a switch.

In summary, you shouldn't have to add any routers if your ISP does EoMPLS.

You can do it to creating a routing layer on your EoMPLS with let say /30 to and then nicely route all between sites, but this is optional if you would have more than one subnet/VLAN on each site.

I would investigate why they are making you get a routers since EoMPLS is not reqiore tehm, but then you are not providing any details so there might be something that I don't know.

Hope that helps!

Hi Lipos / Everyone

I have attached a diagram, showing what I am trying to achieve

We would like to Carry a Dot1q trunk (multiple vlans)  transparently over the STC EoMPLS point to point link as show in the diagram below. We want a flat Layer 2 LAN from end to end with the same IP subnets configured on Riyadh and Qassim VLANS.

As you can see in the diagram on both ends I have a dot1q trunk configured towards STC and vlan 100,200 and 300 allowed on the trunk. However I am not getting an end to end Layer 2 connectivity. For example Vlan 100 in Riyadh ( is not pinging Vlan 100 in Qassim (

The only way I can get it to work or ping is Layer 3 to Layer 3, if I put a Laptop directly on both ends and configure IP on them in same subnet, only then it pings.

We raised a TAC case with the Service Provider and the engineer said on the Qassim end, we cannot connect a Switch directly to the SHDSL modem and we need to connect a Router to the SDSL modem. Is this correct and if so, what is the reason for this?

Also one thing we noticed is that Ping needs to be initiated from Qassim end. If we initiate ping from Riyadh it doesn’t work. I mentioned this to the STC engineer when I opened the TAC case and he asked me to configure SLA Monitor.

Side qaseem

Please put this code under physical interface 

ip sla monitor 1

type echo protocol ipIcmpEcho STC_PE_IP_ADRESS

timeout 100

frequency 1

ip sla monitor schedule 1 life forever start-time now

Obviously this is not correct as the link should be constantly up and pingable, and should not need to be initiated from one end.

Please advise, what do you think it happening and what do I neeed to tell the Service provider?

Thanks in advance...

Diagram is attached to the end of the original post above..(Drawing1.jpg)


By definition an EoMPLS service in port-to-port mode should let you do whatever you want. However, there is another variation of the service which is relaying a specific VLAN across sites. In that case you cannot carry multiple VLANs over the wire unless you do QinQ tunneling on your equipment.

That being said in your scenario a lot depends on the capabilities of the SHDSL modem as well as how the ME3400 has been configured. You should clearly ask the provider that you need a port to port EoMPLS that should allow you to carry multiple VLANs across the provider backbone. How the provider configures it is up to them but in my opinion they should be able to offer this service barring any hardware/software limitation on the SHDSL modem side.


Hi Siddigirf,

To my knowledge, it is possible. I was working on  a similar setup where I had switches connected to PE device as below,

(Multiple networks)---------switch1-------PE1---(MPLS_CLOUD)----PE2-------switch2---------(Multiple networks)

On switch1 and switch2, you need to configure the interface towards PE as trunk. Interface towards internal devices as QinQ interface. Now PE interface should be configured as QinQ using "encapsulation dot1q second-dot1q any". The top-vlan on PE should match the QinQ vlan configured on switches.

This way when any packet received from internal devices on switch1 with any vlan header, it will be encapsulated with second vlan as the incoming interface is marked as QinQ. This will be sent over the trunk interface towards PE (this interface should not be QinQ interface).

PE device on receiving it will decapsulate the top vlan and will send the packet with inner vlan header to remote PE which inturn will be sent with vlan header intat to remote switch.



Amir Aziz

Did you make sure that the MTU size is increased i.e. if the default MTU is 1500 it would need to be 1504 due to additional tagging of VLAN information in the frame header. This would require you to reboot your devices as it is a system-wide configuration. Otherwise, fragmentation would occur and this would cause the QinQ Tunneling protocol to fail. This is my experience and what I have learnt from reading different sources. I hope it helps.