This read-create INTEGER selects which routing protocol (kernel, connected, static, rip, or bgp) is redistributed into OSPF for this table row, and creating the row starts redistribution of that protocol while deleting it stops redistribution; per the MIB, the T4R model only supports connected, rip, and static. An admin creates a row here to have the switch inject routes learned from another source into its OSPF domain, turning it into an ASBR router. Creating a row with ospfRedistributeProtocol set to static(3) would start injecting the switch's manually configured static routes into the OSPF routing domain.