Interior Gateway Routing Protocol (IGRP) processes and Enhanced IGRP (EIGRP) processes with the same autonomous system number (ASN) do not require manual redistribution. Mutual redistribution of IGRP and EIGRP routing processes occurs automatically if the processes share the same ASN; there is no additional configuration required to enable route redistribution between the IGRP and EIGRP processes. However, you must manually configure route redistribution between IGRP and EIGRP processes with different ASNs.

Routing Information Protocol version 2 (RIPv2) automatically redistributes static routes that point to an interface on the router. However, RIP does not redistribute static routes that point to a nexthop IP address unless you issue the redistribute static command from RIP router configuration mode. RIPv2 assigns static routes a metric of 1 and redistributes them as though they were directly connected. Because there is only one routing protocol involved when static routes are redistributed into a RIPv2 routing domain, this is a one way redistribution of routing information.

EIGRP automatically redistributes static routes that point to an interface on the router. However, EIGRP does not redistribute static routes that point to a nexthop IP addressunless you issue the redistribute static command from EIGRP router configuration mode. The static route is redistributed as an external route. Because there is only one routing protocol involved when static routes are redistributed into an EIGRP routing domain, this is a oneway redistribution of routing information.

Open Shortest Path First (OSPF) processes with different process IDs do not redistribute routes without manual configuration. Although it is possible to run multiple OSPF processes on a single router, it is not recommended, because suboptimal routing and routing loops may occur.

Intermediate System-to-Intermediate System (IS-IS) and OSPF processes with the same area number do not redistribute routes without manual configuration. IS-IS and OSPF both assign a default metric to redistributed routes unless otherwise specified.