The only way to accomplish this with older filers via ZAPI is to use the unsupported system-cli call. In Java, this would look something like:
NaElement api = new NaElement("system-cli");
NaElement argsElement = new NaElement("args");
api.addChildElem(argsElement);
argsElement.addNewChild("arg", "ifconfig");
argsElement.addNewChild("arg", "-a");
NaElement output = server.invokeElem(api);
Then write some code to parse out the results via regex. This approach is not with out it's drawbacks.
-ryan