SNMP, MIB, обращение к объектам по именам

$ snmpget -v 1 -c public localhost 1.3.6.1.4.1.1234.1...
...получаю данные

$ snmpget -v 1 -c public localhost 1.3.6.1.4.1.foo.bar...
... Unknown Object Identifier (Sub-id not found: enterprises -> foo)

<?php
        if (snmp_read_mib("FOO_BAR-MIB.mib")) {
		$reply = snmpget("localhost","public","1.3.6.1.4.1.foo.bar...");
...
// Warning: snmpget() [function.snmpget]: Invalid object identifier: 1.3.6.1.4.1.foo.bar...

FOO_BAR-MIB DEFINITIONS ::= BEGIN

        IMPORTS
                enterprises
        FROM RFC1155-SMI
                OBJECT-TYPE
        FROM RFC-1212
                TRAP-TYPE
        FROM RFC-1215;

foo	OBJECT IDENTIFIER ::= { enterprises 1234 }
bar	OBJECT IDENTIFIER ::= { foo 1 }
...