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New Member

AToM traffic-engineering


I have a question regarding how to map a l2circuit to a particular LSP.

We have setup one lab network:

CE1 - PE1 - Px - Py - Pz - PE2 - CE2

What I want to achieve is to map a l2circuit to a particular LSP (tunnel), wich start from PE1, land in Py, is stitched to one another LSP which start on Py and end in PE2 (the P routers are Junipers).

It's a possibility to make this thing working ?

If I configure a direct tunnel between PE1 to PE2 and i configure the tunnel with

tunnel mpls traffic-eng autoroute announce

The VC is up.

But if a try whith the stitched LSP it doesn't work. The VC labels are exchanged, but the VC doesn't come UP:

#show mpls l2transport vc detail

Local interface: PO4/1/0 up, line protocol up, HDLC up

Destination address:, VC ID: 1, VC status: down

Preferred path: not configured

Default path: path untagged

Tunnel label: not ready

Output interface: unknown, imposed label stack {}

Create time: 02:21:31, last status change time: 01:51:56

Signaling protocol: LDP, peer up

MPLS VC labels: local 16, remote 30

Group ID: local 0, remote 0

MTU: local 4470, remote 4470

Remote interface description: Link to FR

Sequencing: receive disabled, send disabled

VC statistics:

packet totals: receive 281, send 0

byte totals: receive 1124, send 0

packet drops: receive 0, send 0

ANybody any ideas how can I make this to work ?

On the other hand there is a Cisco equivalent of the Juniper LSP stitching ?

I will realy need it because if it will be implemented the P routers will be cisco-s.

Thank you

New Member

Re: AToM traffic-engineering

Why don't you create a LSP from PE1 to PE2,

but with explicit-path?

This will probably do what you want?

New Member

Re: AToM traffic-engineering

Hello Zvladov,

Thank you for your response.

The thing is that there are 3 totaly diferent domain, diferent AS-s.

So that why we want diferent LSPs.

I don't think taht is possible to setup LSP trough diferent IGP domains.

Or maybe I'm wrong ?

What I know that with Juniper I can turn of the cspf and I can setup manually the path, maybe also in diferent domains, but with Cisco I don't no how to do that. As far as I know you must have in your IGP all mpls "hops".

Do you know how to avoid this ?


New Member

Re: AToM traffic-engineering

ATOM uses LDP. So ATOM trhough different providers is described at the white paper for ATOM and the configs of 12.2S as possible.

The things is that the tags are exchanged over LDP. That is the key.

You just point-out the IP address of the other ISP under the connect command.

LSP through different ISP - that is another question.

I am not sure about it, I'll have to check out.

Zvezdelin Vladov


Re: AToM traffic-engineering

For creating a Inter-As L2vpn you will need a label for the remote PE's loopback address(tunnel label).

You can send the label with BGP-Send label capability(ipv4 + Label)to the other As to do Lsp-stitching.

pls see the url for more info.

New Member

Re: AToM traffic-engineering

Hello crysm,

If I understand your question correctly, you could use the tunnel selection feature (see link below) to map a certain VC to a certain LSP. That should do the trick for you.



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