Because replaceable static routes are intended to be last-resort routes, TCP/IP attempts to use them only if no dynamic routes to the destination are available.
If a non-replaceable static route fails validation, even if the reason for the failure is transient like gateway unreachable, the definition for the non-replaceable static route is discarded. However, if a replaceable static route fails validation for a transient reason, the definition of the route is retained. When there are no dynamic routes to the destination, TCP/IP periodically tries to add the replaceable static route to the routing table. Because of these periodic attempts, multiple EZZ4333I messages might be seen. Retries are performed no more often than every 30 seconds, and only as long as there are no active routes to the destination in the routing table, and only if at least one new route has been added to the routing table since the last retry. Retries are terminated as soon as a valid route to the destination is installed into the routing table, whether it is dynamic, static, or replaceable static.
For a discussion of things to consider when using IPv4 static routing and OMPROUTE together on the same TCP/IP stack, see Use of static routing with OMPROUTE.