Internet Draft Silvano Gai
draft-gai-fc-mibs-00.txt Keith McCloghrie
Expires: December 2003 Cisco Systems
Claudio DeSanti
Andiamo Systems
June 2003
MIBs Standardization for Fibre Channel
Status of this Memo
This document is an Internet Draft and is in full conformance with
all provisions of Section 10 of RFC 2026.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that
other groups may also distribute working documents as
Internet-Drafts.
Internet-Drafts are draft documents valid for a maximum of six
months and may be updated, replaced, or obsoleted by other
documents at any time. It is inappropriate to use Internet-
Drafts as reference material or to cite them other than as
"work in progress."
The list of current Internet Drafts can be accessed at
http://www.ietf.org/ietf/1id-abstracts.txt
The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html.
Abstract
Fibre Channel (FC) is a high speed serial interface technology that
supports several Upper Layer Protocols including Small Computer
System Interface (SCSI) and IP. Fibre Channel is standardized by the
INCITS T11 Technical Committee. Fibre Channel Standards include
Framing and Signaling protocols [FC-FS], Generic Services protocols
[FC-GS-3], Switch Fabric protocols [FC-SW-2], etc.
The management of a Fibre Channel network requires to monitor and set
many parameters related to these protocols and this may be
accomplished defining a proper set of MIBs.
Gai, McCloghrie, DeSanti Expires December 2003 [Page 1]
INTERNET DRAFT MIBs Standardization for Fibre Channel June 2003
This Internet Draft states the intention of the authors to submit to
the IETF for standardization 9 new MIBs related to all the aspects of
Fibre Channel management. The purpose of this document is to
stimulate a discussion inside the IETF on where this standardization
work can be accomplished and to receive preliminary feedback before
submitting the individual I-Ds.
1. Overview of Fibre Channel
Fibre Channel (FC) is a gigabit speed network technology primarily
used for Storage Networking. Fibre Channel is standardized in the T11
Technical Committee of the InterNational Committee for Information
Technology Standards (INCITS), an American National Standard
Institute (ANSI) accredited standards committee.
Fibre Channel devices are called Nodes. Each Node has one or more
Ports to connect to Ports of other devices. Fibre Channel may be
implemented using any combination of the following three topologies:
- a point-to-point link between two Ports;
- a set of Ports interconnected by a switching network called a
Fabric [FC-SW-2];
- a set of Ports interconnected with a loop topology, as defined in
[FC-AL-2].
A Node Port is more precisely called an N_Port. A Node Port that is
capable of operating in a loop topology using the loop specific
protocols is designated as an NL_Port. The term Nx_Port is used to
generically indicate these two kinds of Node Port.
A Fabric Port is more precisely called an F_Port. A Fabric Port that
is capable of operating in a loop topology using the loop specific
protocols is designated as an FL_Port. The term Fx_Port is used to
generically indicate these two kinds of Fabric Port.
Fibre Channel ports interconnecting Switches are called Expansion
Ports or E_Ports. E_Port operation specifies the tools and algorithms
for interconnection and initialization of Fibre Channel Switches to
create a multi-Switch Fabric [FC-SW-2]. Fabric operation includes
Fabric Configuration, Path Selection, Distributed Server
Communication, Exchange of Zone Information, Distributed Event
Notification, etc.
A Fibre Channel Fabric provides several Generic Services to the nodes
connected to the Fabric itself [FC-GS-3]. Examples of Services are
Directory Services or Management Services. Access to Fabric Services
is provided by a Common Transport Protocol, that provides a set of
parameters that facilitates the usage of Fibre Channel constructs. It
Gai, McCloghrie, DeSanti Expires December 2003 [Page 2]
INTERNET DRAFT MIBs Standardization for Fibre Channel June 2003
also provides a level of multiplexing that simplifies the
Switch-to-Switch communication for a Distributed Service.
2. MIBs for management
Fibre Channel has evolved into an extensive network architecture with
many features, protocols, services and parameters. This has created a
demand for a standard solution for the management of Fibre Channel
networks and for integration with the management of IP networks.
Historically the IETF has used SNMP and MIBs as the primary vehicle
for management information with good success. There has been some
attempts to extend MIBs to cover SANs (Storage Area Networks) with
some relevant successes in the area of SCSI, for example with the
work on Definition of Managed Objects for SCSI Entities done in the
IP Storage WG.
The so called "Fibre Alliance MIB" has also been implemented in many
products, and an updated and corrected version (draft-ietf-ips-
fcmgmt-mib-04.txt) is in the process of being approved as a Proposed
Standard. However, a systematic work of standardization of a set of
MIBs to cover all the different aspects of Fibre Channel networks has
not yet been attempted. Note that the IPS WG did previously consider
defining some of the additional FC functionality in MIBs, but
deferred it to the future (see
http://www.pdl.cmu.edu/mailinglists/ips/mail/msg09473.html).
The authors of this I-D are interested in submitting to the IETF
approximately 9 MIBs that collectively cover all the management
aspects of a Fibre Channel network. A list of the MIBs with a short
description is given in section 4. These MIBs are intended to
complement and update but not obsolete the existing work on Fibre
Channel MIBs that the IETF has done.
The authors ask for guidance from the IETF in identifying the most
appropriate WG that can work on the standardization of these MIBs
before submitting all the individual I-Ds.
3. VSAN awareness
The concept of Virtual Fabric or VSAN (Virtual SAN) [VSAN, TAG-HEAD]
has been recently introduced in Fibre Channel. Similar to VLANs
(Virtual LANs), VSANs allow the sharing of a common Fibre Channel
physical infrastructure by multiple logical Fabrics. The concept of
VSAN is already present in the CIM/SMI-S specification [CMI/SMI-S],
and has been proposed to SNIA and to T11 [VSAN, TAG-HEAD]. All these
MIBs are VSAN-aware.
Gai, McCloghrie, DeSanti Expires December 2003 [Page 3]
INTERNET DRAFT MIBs Standardization for Fibre Channel June 2003
4. List of MIBs
The following MIBs are ready to be submitted for standardization.
4.1 Fibre Element
This MIB covers:
- Extension to the interface MIB [RFC 2863];
- The groups from [RFC 2837] relevant to an FC Fabric;
- Other features specific to an FC Fabric.
This MIB supports all the port types defined by [FC-FS] and [FC-AL-2]
(N_Port, NL_Port, F_Port, FL_Port), all the port types defined by
[FC-SW-2] (E_Ports or B_Ports), plus the port types required to
support VSANs [TAG-HEAD] (TE_Port or Trunking E_Port).
Examples of parameters that can be monitored/configured are:
Buffer-to-Buffer Credits, FC Port Type, Port Name_Identifiers,
Port Speed, Port Status, VSAN list and Login table.
4.2 Virtual Fabrics (VSAN)
This MIB enables the manager to configure and monitor Virtual Fabrics
parameters (see section 3).
Examples of parameters that can be monitored/configured are: Name,
ID, State, MTU, in order delivery, Name_Identifiers, and membership.
4.3 Domain Manager
The Domain Manager is a software functionality present on an FC-SW-2
compliant Switch [FC-SW-2] to provide addresses (domain) assignment.
For the purposes of this MIB, Domain Manager is the software
functionality which executes in both the Principal Switch [FC-SW-2]
and other Switches of a FC Fabric.
Examples of parameters that can be monitored/configured are:
Principal Switch ID, Priority, Domain_ID List.
4.4 Fibre Shortest Path First (FSPF)
Fibre Shortest Path First (FSPF) [FC-SW-2] is a link state path
selection protocol. FSPF keeps track of the state of the links on all
Switches in the Fabric and associates a cost with each link. The
protocol computes paths from a Switch to all the other Switches in
Gai, McCloghrie, DeSanti Expires December 2003 [Page 4]
INTERNET DRAFT MIBs Standardization for Fibre Channel June 2003
the Fabric by adding the cost of all the links traversed by the path,
and choosing the path that minimizes the overall cost. The collection
of link states (including cost) of all the Switches in a Fabric
constitutes the topology database (or link-state database).
This MIB enables the manager to configure and monitor FSPF
parameters.
Examples of parameters that can be monitored/configured are:
Region ID, Domain ID, Interface State, Interface Cost, Interface
Hello Interval, Interface Dead Interval, Hold Time, Max Age, Admin
Status, Operator Status, and Incarnation Number.
4.5 Routing Information
FSPF [FC-SW-2] defines how to compute the shortest path toward
another domain. When this computation is done, it needs to be
summarized into a routing table that define for each destination
domain the next hop(s) and that can be used by a switch forwarding
engine, either centralized or distributed.
This MIB enables the manager to configure and monitor Routing
Information.
Examples of parameters that can be monitored/configured are:
the Fibre Channel Routing table, and for each route the Route
Destination Address ID, Interface, Domain_ID, Route Metric, and Route
Type.
4.6 Name Server
The Name Server [FC-GS-3] provides a way for N_Ports and NL_Ports to
register and discover Fibre Channel attributes. Once registered, the
attributes are made available to requestors. The Name Server is
intended to be distributed among Fabric Elements, making the Name
Server available to N_Ports and NL_Ports, once they have successfully
completed Fabric Login. For example, a disk may register with the
name server to become known to the hosts. An host, after having
completed the Fabric Login may query the name server to discover
which disks are accessible.
This MIB enables the manager to configure and monitor the Fibre
Channel Name Server.
Examples of parameters that can be monitored/configured are:
the Fibre Channel Name Server table, which contains an entry for each
Nx_Port presently known (through FC-GS-3 registrations) and in each
Gai, McCloghrie, DeSanti Expires December 2003 [Page 5]
INTERNET DRAFT MIBs Standardization for Fibre Channel June 2003
entry the Port Name, the Node Name, Class of Service, Node IP
address, FC-4 Type, Port IP address, Symbolic Port Name, and Symbolic
Node Name.
4.7 Registered State Change Notification (RSCN)
RSCNs [FC-FS] are messages sent to registered Nx_Ports when an event
occurs which may have affected the state of one or more Nx_Ports.
RSCNs are intended to provide a timely indication of changes in nodes
to avoid the considerable traffic that polling can generate. RSCNs
may be used to indicate a failed node, allowing the release of
resources tied up by the failed node. RSCNs may also be used to
notify interested nodes of new devices coming on-line, and of changes
within an on-line node that affect the operation of the system (e.g.,
more storage has become available).
This MIB enables the manager to configure and monitor the Fibre
Channel Registered State Change Notification (RSCN).
Examples of parameters that can be monitored/configured are:
the number and a table of Nx_Ports currently registered to receive
RSCNs, and for each Nx_Port the FC_ID of the port and the type of
events included in the subscription. Moreover, statistical
information like the number of SCR, RSCN, SW_RSCN received,
transmitted, accepted and rejected are provided.
4.8 Zone Server
Fabric Zones [FC-GS-3, FC-SW-2] provide a mechanism to expose
selected views of Name Server information to Clients. This technique
is similar to “virtual private networks” in that the Fabric can group
Fibre Channel address identifiers into Zones. Administrators create
Zones to increase network security, and prevent data loss or
corruption, by controlling access between devices or user groups.
A Zone Server maintains a list of all the Zone Sets configured. A
Zone Set is a collection of Zones. There may be multiple Zone Sets
configured on a Fabric. Only one Zone Set is allowed to be active at
a time. A Zone can be present in multiple Zone Sets. Each Zone
consists of a group of members allowed to communicate.
Zones and Zone Sets may be configured and monitored through a Switch
vendors' management tool, or via this MIB.
Examples of parameters that can be monitored/configured are:
Zone Set database, Active Zone Set, and for each Zone Set the Index,
the Name, the Zone List, the Administrator Status and the Operative
Gai, McCloghrie, DeSanti Expires December 2003 [Page 6]
INTERNET DRAFT MIBs Standardization for Fibre Channel June 2003
Status. For each Zone the Index, the Name, the Member List and the
Alias List.
4.9 Fabric Configuration Server
As a repository for configuration information, the Fabric
Configuration Server [FC-GS-3] provides information regarding the
Fabric, and the Interconnect Elements that comprise the Fabric. It
provides a way for a management application to discover Fibre Channel
Fabric topology information and attributes. The Fabric Configuration
Server is intended to be distributed among Fabric Elements, making
the Fabric Configuration Server immediately available to an N_Port
once it has successfully completed the Fabric Login. Requests for the
Fabric Configuration Server are carried over the Common Transport.
This MIB module interfaces the Fabric Configuration Server (FCS).
Examples of parameters that can be monitored/configured are:
the Interconnect Elements table, composed of Interconnect Element
entries, each having a Name, a Type, a Domain_ID, a Management_ID, a
Fabric_Name, a Logical Name; and a Port List Table, composed of Port
List entries, each having a Port Type, a Port Name, a Port State and
an Attached Port Name.
5. Security Considerations
These MIBs do not introduce any additional security concerns beyond
what already exists within the Fibre Channel protocols.
There are a number of management objects defined in this MIB that
have a MAX-ACCESS clause of read-write and/or read-create. Such
objects may be considered sensitive or vulnerable in some network
environments. The support for SET operations in a non-secure
environment without proper protection can have a negative effect on
network operations.
In particular, write-able objects allow an administrator to control
the interfaces or to perform tests on the interfaces, and
unauthorized access to these could cause a denial of service, or in
combination with other (e.g., physical) security breaches, could
cause unauthorized connectivity to a device.
SNMPv1 by itself does not provide a secure environment. Even if the
network itself is secure (for example by using IPsec), even then,
there is no control as to who on the secure network is allowed to
access and GET/SET (read/change/create/delete) the objects in a MIB.
Gai, McCloghrie, DeSanti Expires December 2003 [Page 7]
INTERNET DRAFT MIBs Standardization for Fibre Channel June 2003
It is recommended that the implementers consider the security
features provided by the SNMPv3 framework. Specifically, the use of
the User-based Security Model specified in [RFC 2574] and the View-
based Access Control Model [RFC 2575] is recommended.
It is then a customer/user responsibility to ensure that the SNMP
entity giving access to an instance of a MIB, is properly
configured to give access to the objects only to those principals
(users) that have legitimate rights to indeed GET or SET
(change/create/delete) them.
6. Acknowledgment
The authors would like to acknowledge all the individual authors of
the MIBs.
7. References
[FC-FS] ANSI INCITS 373-2003, "Fibre Channel - Framing and
Signaling (FC-FS)".
[FC-AL-2] ANSI INCITS 332-1999, "Fibre Channel - Arbitrated Loop-2
(FC-AL-2)".
[FC-GS-3] ANSI INCITS 348-2000, "Fibre Channel - Generic Services-3
(FC-GS-3)".
[FC-SW-2] ANSI INCITS 355-2001, "Fibre Channel - Switch Fabric-2
(FC-SW-2)".
[RFC 2574] Blumenthal, U. and B. Wijnen, "User-based Security Model
(USM) for version 3 of the Simple Network Management
Protocol (SNMPv3)", RFC 2574, January 1998.
[RFC 2575] Wijnen, B., Presuhn, R. and K. McCloghrie, "View-based
Access Control Model (VACM) for the Simple Network
Management Protocol (SNMP)", RFC 2575, January 1998.
[RFC 2837] Teow K.S., "Definitions of Managed Objects for the Fabric
Element in Fibre Channel Standard", RFC 2837, May 2000.
[RFC 2863] McCloghrie K., Kastenholz F., "The Interfaces Group MIB",
RFC 2863, June 2000.
[VSAN] DeSanti C., Carlson C., McGlaughlin E. "Virtual Fabrics"
T11 document 03-352v0, May 2003.
Gai, McCloghrie, DeSanti Expires December 2003 [Page 8]
INTERNET DRAFT MIBs Standardization for Fibre Channel June 2003
[TAG-HEAD] DeSanti C., Carlson C., McGlaughlin E. "Tagged Frame
Specification" T11 document 03-353v0, May 2003.
[CMI/SMI-S] SNIA CIM/SMI-S: Storage Management Initiative
Specification, Version 1.1.
8. Authors' Address
Silvano Gai
Cisco Systems, Inc.
170 West Tasman Dr.
San Jose, CA 95134
USA
Phone: +1 408 527-7269
EMail: sgai@cisco.com
Keith McCloghrie
Cisco Systems, Inc.
170 West Tasman Dr.
San Jose, CA 95134
USA
Phone: +1 408 526-5260
EMail: kzm@cisco.com
Claudio DeSanti
Andiamo Systems, Inc.
375 E. Tasman Dr.
San Jose, CA 95134
USA
Phone: +1 408 853-9172
EMail: cds@andiamo.com
Gai, McCloghrie, DeSanti Expires December 2003 [Page 9]