How RLM Clients Find the License Server

There are a number of ways for RLM clients to locate a license server. These include:

  • A HOST (or SERVER) line in a local license file. specified by:

    • A license filename passed as argument 1 to rlm_init()

    • A license filename contained in a directory passed as argument 1 to rlm_init()

    • A license filename in the application binary directory, as passed in argument 2 to rlm_init()

    • A license file referenced from the RLM_LICENSE or ISV_LICENSE environment variable.

  • A port@host specification contained in the RLM_LICENSE or ISV LICENSE environment variable.

  • If none of these methods work to locate a license server, the RLM client will broadcast to find a license server on the local area network.

Note

Reprise Software recommends placing your license file in the directory with your binary, and passing this directory name (usually “.”) as the 2nd argument to rlm_init().

If you use a license server, this license file need only contain a single HOST (or SERVER) line with the correct hostname (and port if you don’t use the default port). The hostid in this license file does not matter. So, for example, if your license server is on machine paradise at the default port (5053), this license file can contain this single line:

HOST paradise any

Broadcasting to find the license server

RLM clients can broadcast on the local network to find a license server.

Note

Broadcasts do not travel through routers, so this is only effective for smaller networks.

This can be quite useful for installations at smaller customer sites which have no full-time IT personnel.

The broadcast has the following characteristics:

  • If a license server for your ISV name is located using any other method, then the broadcast will not be performed.

  • The first server to answer the broadcast will be used. Generally, since this is a small network, there will only be one.

  • The broadcast will always happen on UDP port 5053, which has been assigned to Reprise Software by the Internet Assigned Numbers Authority (iana.org).

  • The client waits for a reply for 2 seconds. This is not configurable.

  • You can disable this broadcast in your software by calling rlm_isv_cfg_disable_broadcast() in your rlm_isv_config.c file (or any time after you call rlm_init() and before you check out a license).