Refer to the exhibit A customer network design team is planning a migration from a legacy TDM- based L2VPN to an MPLS-based L3VPN Migration is planned in a phased approach: - OSPF backbone Link…

Applying route filtering on OSPF backbone routers treats individual symptoms rather than systematically eliminating the redistribution conditions that cause loops during dual-protocol migration.

Advertising a low administrative distance for transit traffic makes OSPF routes more preferred than BGP routes, causing suboptimal path selection rather than preventing routing loops.

When OSPF and eBGP coexist during the transition, the hub sites risk learning specific spoke routes via BGP and then redistributing them back into OSPF, which re-advertises them into BGP and creates a loop; summarizing OSPF backbone routes to the hub removes the more-specific routes that would otherwise cycle between protocols.

Redistributing EIGRP 200 and 300 into BGP is irrelevant because the scenario involves an OSPF backbone being migrated to eBGP, with no EIGRP in the described topology.