OSPF VRF LITE

Hi All,

 

I am just trying to understand the scenario for VRF LITE (I have the same kind of post previously):

I have topology like R1-R2-R3-R4-R5, R2/R3/R4 are part of AS1 and R1 and R5 are client!

I have configure the VRF VPNA on R1/R2/R4/R5 with same RD/RT value and running OSPF there as CE-PE,

now with out adding the capability vrf-lite on R1 and R5, I can see OSPF routes in only PEs for respective connected CEs and remote CEs, but CEs doesn't have routes to each other!!! so to get the routes in the routing tables of CE i have to configure the DOMAIN-ID in on one of the PE router, using this I can see the remote CE routes in local CE with "E2"!!! why domain-ID workes here? normally domain id is used to control the LSA type generation!!! right!!!

other case, as soon as I configure the CAPABILITY VRF LITE on CE routers OSPF process, I can see the remot CE routes as "IA" in local router (here we donot need to have the domain-id configured on PE routers to get the remote CE update.)

 

I am just trying to clear the understanding why it is working in this way!!! how domain-id on PE plays the role in absense of capabilty vrf-lite on CE!!!

 

regards

Dev

Comments



  • Re: [CCIE SP] OSPF VRF LITE


    In a nutshell “domain-id” will help when you loose a link on your CE side when you have more than one CE connected to PE nodes. In other words an OSPF area contain routers and multi-homed to 2 or more PE routers. Then if they become disconnected then the “domain-id” will allow the ospf process not to block it as it is receiving routes from it’s ospf domain.



    Vrf-lite is used between the CE & PE. By enabling vrf-lite you are switching “off” route check mechnisms to allow the routes into the ospf on the CE devcie thus enabling a “full” routing table.



    If you watch the IE SP DVD on the vrf-lite set-up it explains it nicely :-) Be a good man and get your hands on that SPDVD :-) It is a life saver.



    Thanks



    James





    On 10/26/08 8:10 PM, "dev13" <[email protected]> wrote:



    Hi All,



     



    I am just trying to understand the scenario for VRF LITE (I have the same kind of post previously):



    I have topology like R1-R2-R3-R4-R5, R2/R3/R4 are part of AS1 and R1 and R5 are client!



    I have configure the VRF VPNA on R1/R2/R4/R5 with same RD/RT value and running OSPF there as CE-PE,



    now with out adding the capability vrf-lite on R1 and R5, I can see OSPF routes in only PEs for respective connected CEs and remote CEs, but CEs doesn't have routes to each other!!! so to get the routes in the routing tables of CE i have to configure the DOMAIN-ID in on one of the PE router, using this I can see the remote CE routes in local CE with "E2"!!! why domain-ID workes here? normally domain id is used to control the LSA type generation!!! right!!!



    other case, as soon as I configure the CAPABILITY VRF LITE on CE routers OSPF process, I can see the remot CE routes as "IA" in local router (here we donot need to have the domain-id configured on PE routers to get the remote CE update.)



     



    I am just trying to clear the understanding why it is working in this way!!! how domain-id on PE plays the role in absense of capabilty vrf-lite on CE!!!



     



    regards



    Dev









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