Need advice from expert, currently I work for MPLS network migration,
the customer have 2 existing MPLS network with different AS number.
Old AS (AS65002) has existing old PE, RR and VRF service (VRF more than 1000).
New AS (AS65003) has existing PE, RR and VLL & VRF service (VRF & VLL more than 2000).
Customer want to expand coverage area of MPLS domain AS65003 by install new PE type
which running IGP ISIS and BGP same with PE in MPLS AS65003 and replace existing old PE in MPLS AS65002.
That means all of old VRF in old PE AS65002 must be migrated to new PE in AS65003.
All of new PE in MPLS AS65003 is ASBR (more than 100),
Each new PE has 2 link connect by dual homing point to differrent 2 ASBR (old) PE in MPLS AS65002.
Requirement from customer
1. Traffic for old VRF in AS65002 (but already migrate to new PE in AS65003) should via old core AS65002
2. ASBR in each MPLS network dont want to participated with routes in each VRF (may be Inter-AS option C will meet the requirement?)
3 type of VRF traffic in new PE MPLS AS65003
VRF type 1:
Traffic AS 65003 -> 65002 (e.g. Internet service)
Traffic AS 65003 -> 65002 -> 65003 (e.g. peer to peer traffic in VRF internet service)
VRF type 2:
Traffic 65003 -> 65002 (in case of PE in different AS)
Traffic 65003 -> 65002 -> 65003 (in case of PE in same AS65003)
(e.g. old corporate VRF service in 65002)
VRF type 3:
Traffic 65003 -> 65003
(e.g. corparate VRF service in 65003)
What is the solution of Inter-AS provider should be apply for this scenario?
How to control VRF traffic for all of 3 type with different path between 2 MPLS network?
How to share load of traffic between new PE (ASBR) in MPLS AS65003 Inter-AS with 2 of ASBR (PE) in MPLS AS65002?
How to prevent BGP routing loop?
If all of old PE in MPLS AS65002 running global multicast with pim spase mode, SSM & anycast RP, After migrate to new PE, How about multicast?
What is solution for multicast migration between different MPLS domain? Inter-domain by multicast BGP & MSDP?
Thank you for your kindly advice.