Impact of IP Aggregation on LSPs

IP aggregation/sumerisation breaks an LSP into 2 segments

• Aggregation should not be used where end-to-end LSP’s are required such as witin;
• MPLS VPNs
• MPLS TE
• MPLS enabled ATM network
• Transit BGP where core routers are not running BGP

Label allocatation and distribution in a frame-mode MPLS network follows these steps;

• IP routing protocol build the IP routing table
• Each LSR assigns a label to every destination in the IP routing table independently
• LSRs announce their assigned labels to all other LSRs
• Every LSR builds its LIB, LFIB and FIB data structures based on received labels