General MPLS questions

Unanswered Question
Mar 31st, 2009

Hi, All,

I am new to MPLS. Currently I have three branches connected to my Central location. My central location used 2800 series router and three branches all use 1800 series router (with T1 WIC modules). Currently, each branch connects to the central location using point-to-point private T1. We are running EIGRP for routing. Because T1 cost is high, my boss wants to change T1 to MPLS. A MPLS service provider for MPLS told me that they will install MPLS line and install a PE router at each location.

I am new to MPLS so I have some general questions. All I try to do is to replace my T1 with MPLS. I am not familiar with MPLS. Not sure if it is a layer 2 or layer 3 technology.

1. Is MPLS line private like T1? Layer 2 or layer 3?

2. Typically MPLS provider installed a PE router at the site, do they provide me an ethernet port or serial port? My T1 is serial line.

3. If they provide me an ethernet port for me to connect my device, can I still use my private IP address scheme (192.168.X.1) for the my router's interface that connects to PE? I still want to manage the devices and routers that we owned.

4. Does my router IOS need to enable MPLS? If the provider's PE router is the edge router that connect MPLS to non-MPLS

I don't need to enable MPLS in my router, right?

5. Can I still run EIGRP?

Thanks in advance.

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Overall Rating: 5 (2 ratings)
shivlu jain Tue, 03/31/2009 - 22:18


1. There is nothing like MPLS. If your service provider is the same then there is no requirement to change the line becasue MPLS is technology, It has nothing to do with physical.

2. MPLS PE should be the SP end, there is no requirement to install PE at each of your branch location. MPLS works on ethernet or serial also.

3. THE prime advantage of using MPLS is that you can run any ip schema and shoudl be unique within your cloud. For PE-CE ip addressing may be SP use public ip addresses.

4.No need to upgrade the IOS of your router becasue MPLS works at SP end. IOS need to be upgraded only that time if you want to run vrf lite.

5.Yes, you cans till use the Eigrp in your cloud but for PE-CE use BGP.


shivlu jain

Harold Ritter Wed, 04/01/2009 - 06:07


EIGRP is also an option as your PE-CE routing protocol but I do agree with you that most SP will prefer BGP.


shivlu jain Wed, 04/01/2009 - 07:01


You are very much right but most of the service proivder don't offer except BGP or static. For policy routing BGP is the best option.


shivlu jain

Harold Ritter Wed, 04/01/2009 - 08:06


I do agree that BGP provides a clean separation between the PE and CE but I know plenty of SPs offering EIGRP and OSPF as a PE-CE routing protocol to their customer. The decision sometime lies in the customer hands (when they can apply enough pressure on the SP ;-) In those cases, you may want to keep your options open.



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