OSPF Design with Multiple MPLS Circuits

[tyagi.v]

Hi,

as per attached topology where exactly we can place our OSPF Area-0  , basically in case of a single MPLS provider we can make it as SUPER OSPF AREA , but what will happen in case we have two or more MPLS links from different ISP's.

Vijay

[Marwan ALshawi]

What is then routing used from the core to each ISP ? And from each CE to the ISP ?

What's the routing between the core and the two routers over thebpoint to point links ?

[tyagi.v]

Its BGP between CE & PE , and static routers every where else.

[Marwan ALshawi]

Well you can do it in many ways but based on your digram if it's not missing any link then I think the bellow design will efficient fornyour network

As mentioned CEs to PEs all bgp

I am assuming the other remote routers over the point to point links are not connected between each other using a shared LAN or a backdoor link

Then configure the link between the Core routers in area 0

Configure the p2p link from each core to the romte router in an area

From each core send a summary route of the bgp routes over the point to point link from each core

If you want e drugging to go over to the core even if therenis internetn then you can make the area between the core and the other end routernover the point ot point link as totally stubby area in the case case the core will send only default route to the remote router over the point to point link

Hope this help

If helpful rate

[tyagi.v]

appreciate you suggestions but ultimately we have run OSPF on entire network between CE & PE also , so in that case where exactly we can design Area0 , as we r having two different MPLS clouds from different ISP's.

[Marwan ALshawi]

Ok I am not sure and why you run bgp and ospf with your ISP at the same time !

Anyway what you could do in each CE conger two ospf instances/processes each one to bu used with diifrent ISP using aera 0 in each

And you can redistribute between these ospf processes and the redistributed route will look like external route

Hope this help

[tyagi.v]

Ok I am not sure and why you run bgp and ospf with your ISP at the same time ! ---- As of now its BGP between CE & PE but we will migrate to OSPF between CE & PE too.

[Marwan ALshawi]

Ok you can use on the core three ospf instances one to each ISP and the third one to the point to point link and you can redistribute between them selectively using ACL or route-maps

Hope this help