Solved: MPLS network design questions

hserhan75 · ‎08-25-2014

we have in our company 230 remote sites, and we are changing all of our circuits to MPLS. wondering if i need to get a high end router in our Data Center? currently we have 3925. also what is the best routing protocol to use in this kind of network? Eigrp or ospf? MPLS will be hosted by the service provider

michael o'nan · ‎08-27-2014

You are controlling your lab. The provider wants to control all routes. I have multiple large MPLS deployments with BGP with up to 500 locations and a couple multi site deployments where they used EIGRP. Each time I used a routing protocol other than BGP I had to create a ticket to advertise a new subnet. Talk to your provider about their requirements.

View solution in original post

michael o'nan · ‎08-25-2014

In the past I typically use BGP as the provider (again my experience) has asked for specific subnets that they will advertise for me through EIGRP or OSPF. I have found that BGP was much easier to work with in this type of scenario. Depending on your data center traffic would help determine what kind of router you need but a 3925 would possibly. work.

hserhan75 · ‎08-26-2014

Thanks for the reply, Michael! why do you think BGP is easier in this scenario?

michael o'nan · ‎08-26-2014

I have found that the provider typically wants to know exactly what routes you will be advertising when using EIGRP or OSPF. This is something they will have to configure on their network to allow. For example EIGRP routes flow from Site A to Site B and you have a new subnet to use for an application. You put the proper network statements in EIGRP and are not learning routes on the other side. You would then have to fill out a form or call a support number to get your new network to the other side.

With BGP there is much more control over what you can advertise with adding networks. With 230 sites you will feel the benefit quickly if you start growing and adding subnets in data centers or additional sites.

hserhan75 · ‎08-27-2014

Thanks again for the reply, Michael! I have a test Lab for MPLS, and i do have Eigrp on the customer side, i do not need to add anything on the MPLS cloud about the routes i am advertising. not sure why the provider will need to know about my routes. they just need to know my Eigrp Autonomous number and that’s it. That’s what I can see in my lab at least, maybe will have to check with the provider about that. I think you need to inform the provider about your routes if you are using static routes instead of dynamic.

michael o'nan · ‎08-27-2014

You are controlling your lab. The provider wants to control all routes. I have multiple large MPLS deployments with BGP with up to 500 locations and a couple multi site deployments where they used EIGRP. Each time I used a routing protocol other than BGP I had to create a ticket to advertise a new subnet. Talk to your provider about their requirements.

hserhan75 · ‎08-28-2014

You are right, i will have to inform the provider if i need to add a subnet if i am using Eigrp or OSPF. do you have by any chance a sample config for a CE router? would like to get an idea of how to configure the BGP on my router.

michael o'nan · ‎08-28-2014

If you want to learn BGP and its capabilities I highly recommend using the free labs at gns3 vault (link below). This is how I learned most everything related to BGP and helped major when I worked for an ISP. If you sign up to be a member you can see the comments and most people post their configuration for the lab. This would give you a good idea of how your configuration will look. BGP is a long topic but definitely worth understanding! Good luck on your journey!

http://gns3vault.com/labs/bgp/