#### 10.3.2 IIOP Configuration Parameters

    ###############################################################################
    # IIOP parameters
    #

    [iiop]

    ###############################################################
    # IIOP Global Settings

    # Preference level for IIOP
    #polyorb.binding_data.iiop.preference=0

    # IIOP's default address
    #polyorb.protocols.iiop.default_addr=127.0.0.1

    # IIOP's default port
    #polyorb.protocols.iiop.default_port=2809

    # IIOP's alternate addresses
    #polyorb.protocols.iiop.alternate_listen_addresses=127.0.0.1:2810 127.0.0.1:2820

    # Default GIOP/IIOP Version
    #polyorb.protocols.iiop.giop.default_version.major=1
    #polyorb.protocols.iiop.giop.default_version.minor=2

    ###############################################################
    # IIOP 1.2 specific parameters

    # Set to True to enable IIOP 1.2
    #polyorb.protocols.iiop.giop.1.2.enable=true

    # Set to True to send a locate message prior to the request
    #polyorb.protocols.iiop.giop.1.2.locate_then_request=true

    # Maximum message size before fragmenting request
    #polyorb.protocols.iiop.giop.1.2.max_message_size=1000

    ###############################################################
    # IIOP 1.1 specific parameters

    # Set to True to enable IIOP 1.1
    #polyorb.protocols.iiop.giop.1.1.enable=true

    # Set to True to send a locate message prior to the request
    #polyorb.protocols.iiop.giop.1.1.locate_then_request=true

    # Maximum message size before fragmenting request
    #polyorb.protocols.iiop.giop.1.1.max_message_size=1000

    ###############################################################
    # IIOP 1.0 specific parameters

    # Set to True to enable IIOP 1.0
    #polyorb.protocols.iiop.giop.1.0.enable=true

    # Set to True to send a locate message prior to the request
    #polyorb.protocols.iiop.giop.1.0.locate_then_request=true

`default_addr` specifies a listening endpoint address, and `alternate_listen_addresses` specifies a whitespace-separated list of additional listening endpoint addresses. The value of `default_addr`, and each element of `alternate_listen_addresses`, have a similar format: `<bind-addr>`[ <pub-addr>]: <port-hint>

`bind-addr` is the address on which to listen to, as passed to the bind(2) system call. The default value is 0.0.0.0 (i.e., listen for incoming connections on all addresses of the local host). If an IP address is specified, it will be used instead. If a host name is specified, it will be resolved, and connections will be listened for on each returned IP address.

`pub-addr` is the address to be published in constructed object references. In particular, this is what appears in IORs produced by the `Object_To_String` CORBA function. If not specified, this defaults to the same as `bind-addr`, except if `bind-addr` is 0.0.0.0 (the default value), in which case the default `pub-addr` is the first non-loopback IP address found to be associated with the local host name.

`<port-hint>` may be a specific port number, or a range of ports separated by an hyphen. If specified, the listening port will be assigned in the indicated range. If not, a random port will be selected by the operating system.

Any of the three components can be omitted. The following are examples of valid listening address specifications:

    0.0.0.0
    # Bind on 0.0.0.0, publish first IP address of local host

    1.2.3.4
    # Bind on 1.2.3.4, publish "1.2.3.4"

    1.2.3.4[server.example.com]
    # Bind on 1.2.3.4, publish as "server.example.com", no specified port

    server.example.com
    # Bind on all IP addresses associated with "server.example.com", publish
    # "server.example.com"

    [server.example.com]
    # Bind on 0.0.0.0, publish "server.example.com"

If PolyORB is compiled with GNATCOLL support, macro substitution may be used in listening address specifications. For example, the following setting directs PolyORB to listen on port 1234 on all local addresses, and publish the local host name:

    [iiop]
    polyorb.protocols.iiop.default_addr=[$hostname]:1234
    # <bind-addr> is unspecified, so defaults to 0.0.0.0
    # <pub-addr> is the local hostname, from built-in macro $hostname
    # <port-hint> is specified explicitly as 1234