Network Working Group D. Thaler
Request for Comments: 4087 Microsoft
Obsoletes: 2667 June 2005
Category: Standards Track
IP Tunnel MIB
Status of This Memo
This document specifies an Internet standards track protocol for the
Internet community, and requests discussion and suggestions for
improvements. Please refer to the current edition of the "Internet
Official Protocol Standards" (STD 1) for the standardization state
and status of this protocol. Distribution of this memo is unlimited.
Copyright (C) The Internet Society (2005).
This memo defines a Management Information Base (MIB) module for use
with network management protocols in the Internet community. In
particular, it describes managed objects used for managing tunnels of
any type over IPv4 and IPv6 networks. Extension MIB modules may be
designed for managing protocol-specific objects. Likewise, extension
MIB modules may be designed for managing security-specific objects.
This MIB module does not support tunnels over non-IP networks.
Management of such tunnels may be supported by other MIB modules.
This memo obsoletes RFC 2667.
Over the past several years, there has been a number of "tunneling"
protocols specified by the IETF (see [RFC1241] for an early
discussion of the model and examples). This document describes a
Management Information Base (MIB) module used for managing tunnels of
any type over IPv4 and IPv6 networks, including Generic Routing
Encapsulation (GRE) [RFC1701,RFC1702], IP-in-IP [RFC2003], Minimal
Encapsulation [RFC2004], Layer 2 Tunneling Protocol (L2TP) [RFC2661],
Point-to-Point Tunneling Protocol (PPTP) [RFC2637], Layer 2
Forwarding (L2F) [RFC2341], UDP (e.g., [RFC1234]), Ascend Tunnel
Management Protocol (ATMP) [RFC2107], and IPv6-in-IPv4 [RFC2893]
tunnels, among others.
Thaler Standards Track [Page 1]RFC 4087 IP Tunnel MIB June 2005
Extension MIB modules may be designed for managing protocol-specific
objects. Likewise, extension MIB modules may be designed for
managing security-specific objects (e.g., IPsec [RFC2401]), and
traffic conditioner [RFC2474] objects.
2. The Internet-Standard Management Framework
For a detailed overview of the documents that describe the current
Internet-Standard Management Framework, please refer to section 7 of
RFC 3410 [RFC3410].
Managed objects are accessed via a virtual information store, termed
the Management Information Base or MIB. MIB objects are generally
accessed through the Simple Network Management Protocol (SNMP).
Objects in the MIB are defined using the mechanisms defined in the
Structure of Management Information (SMI). This memo specifies a MIB
module that is compliant to the SMIv2, which is described in STD 58,
RFC 2578 [RFC2578], STD 58, RFC 2579 [RFC2579] and STD 58, RFC 2580
This MIB module contains two current tables and one deprecated table.
The current tables are:
o the Tunnel Interface Table, containing information on the tunnels
known to a router; and
o the Tunnel Inet Config Table, which can be used for dynamic
creation of tunnels, and also provides a mapping from endpoint
addresses to the current interface index value.
The version of this MIB module that appeared in RFC 2667 contained
the Tunnel Config Table, which mapped IPv4 endpoint addresses to
interface indexes. It is now deprecated in favor of the Tunnel Inet
3.1. Relationship to the Interfaces MIB
This section clarifies the relationship of this MIB module to the
Interfaces MIB [RFC2863]. Several areas of correlation are addressed
in the following subsections. The implementor is referred to the
Interfaces MIB document in order to understand the general intent of
Thaler Standards Track [Page 2]RFC 4087 IP Tunnel MIB June 20053.1.1. Layering Model
Each logical interface (physical or virtual) has an ifEntry in the
Interfaces MIB [RFC2863]. Tunnels are handled by creating a logical
interface (ifEntry) for each tunnel. These are then correlated,
using the ifStack table of the Interfaces MIB, to those interfaces on
which the local IPv4 or IPv6 addresses of the tunnels are configured.