HP StorageWorks 8B - FC Entry Switch User manual

user's guide
version 3.0
isl trunking
www.hp.com

Notice
© Hewlett-Packard Company, 2001. All rights reserved.
Edition: E1201
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ISL Trunking User’s Guide iii
Contents
Preface
About This Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v
Related Publications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v
Getting Help . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii
Getting Software Updates. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii
Chapter 1 Introducing ISL Trunking
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
Advantages of ISL Trunking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
Trunking Groups, Ports and Masters . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
Chapter 2 Installing ISL Trunking
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
Installing ISL Trunking through Telnet . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
Installing ISL Trunking through Web Tools. . . . . . . . . . . . . . . . . . . . . . 2-2
Chapter 3 Using ISL Trunking
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
Administering ISL Trunking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
Frequently Asked Questions about ISL Trunking . . . . . . . . . . . . . . . . . 3-4
Glossary
Index

iv ISL Trunking User’s Guide

ISL Trunking User’s Guide v
Preface
ISL Trunking is a licensed option that requires a valid license key to function. It is included and
enabled in switches with the performance upgrade option. It is supported for the HP Surestore FC
1Gb/2Gb Entry Switch 8B, FC 1Gb/2Gb Switch 8B, and FC 1Gb/2Gb Switch 16B products using
Fabric OS version 3.0.1b or later.
About This Guide
This guide provides the following information about ISL Trunking:
Related Publications
Related product information can be found in the following publications.
Provided with the FC Entry Switch 8B and FC Switch 8B:
•HP Surestore FC 1Gb/2Gb Entry Switch 8B and FC 1Gb/2Gb Switch 8B Getting Started
Guide (A7346-90902)
•HP Surestore FC 1Gb/2Gb Entry Switch 8B and FC 1Gb/2Gb Switch 8B Documentation
CD (A7346-11001)
Chapter 1
Introducing ISL Trunking Overview of the ISL Trunking feature.
Chapter 2
Installing ISL Trunking Instructions for installing an ISL Trunking license key.
Chapter 3
Using ISL Trunking Information on how to use the ISL Trunking feature with telnet commands or Web Tools. This chapter also includes a
Frequently Asked Questions section.

vi ISL Trunking User’s Guide
Provided on the FC Entry Switch 8B and FC Switch 8B Documentation CD, and at the HP Web site
at http://www.hp.com/support/fc8B:
•HP Surestore FC 1Gb/2Gb Entry Switch 8B and FC 1Gb/2Gb Switch 8B Getting Started
Guide (A7346-90902)
•HP Surestore FC 1Gb/2Gb Entry Switch 8B and FC 1Gb/2Gb Switch 8B Installation and
Reference Guide
•Fabric OS Reference Manual, version 3.0
•Fabric OS Procedures Guide, version 3.0
•Fabric OS Version 3.0.1b Release Notes
•Fabric Watch User’s Guide, version 3.0
•QuickLoop User’s Guide, version 3.0
•Web Tools User’s Guide, version 3.0
•Distributed Fabrics User’s Guide, version 3.0
•Zoning User’s Guide, version 3.0
•MIB Reference Manual, version 3.0
•ISL Trunking User’s Guide, version 3.0
•Advanced Performance Monitoring User’s Guide, version 3.0
•Merging Heterogeneous Fabrics Instructions
Provided with the FC 16B:
•HP Surestore FC 1Gb/2Gb Switch 16B Quick Start Guide (A7340-96002)
•HP Surestore FC 1Gb/2Gb Switch 16B Documentation CD (A7340-11001)
Provided on the FC 1Gb/2Gb Switch 16B Documentation CD and at the HP Web site at
http://www.hp.com/support/fc16B:
•HP Surestore FC 1Gb/2Gb Switch 16B Quick Start Guide (A7340-96002)
•HP Surestore FC 1Gb/2Gb Switch 16B Installation and Reference Guide
•Fabric OS Reference Manual, version 3.0
•Fabric OS Procedures Guide, version 3.0
•Fabric OS Version 3.0.1 Release Notes
•Fabric Watch User’s Guide, version 3.0
•QuickLoop User’s Guide, version 3.0
•Web Tools User’s Guide, version 3.0
•Distributed Fabrics User’s Guide, version 3.0
•Zoning User’s Guide, version 3.0
•MIB Reference Manual, version 3.0
•ISL Trunking User’s Guide, version 3.0
•Advanced Performance Monitoring User’s Guide, version 3.0
•Merging Heterogeneous Fabrics Instructions
Information about Fibre Channel standards and Fibre Channel in general can be found on the Fibre
Channel Industry Association Web site, located at http://www.fibrechannel.com.

ISL Trunking User’s Guide vii
Getting Help
For information for the FC Entry Switch 8B and FC Switch 8B, visit the HP Web site at
http://www.hp.com/support/fc8B.For the most current technical support information for the
FC 16B, visit the HP Web site at http://www.hp.com/support/fc16B. This includes hardware and
software support, all repairs, and spare components.
Be prepared to provide the following information to the support personnel:
•Switch serial number
•Switch world wide name
•Output from the supportShow telnet command
•Detailed description of the problem
•Topology configuration
•Troubleshooting steps already performed
Getting Software Updates
For information on obtaining software updates contact your HP account representative or technical
support.

viii ISL Trunking User’s Guide

ISL Trunking User’s Guide 1-1
Chapter
1
Introducing ISL Trunking
This chapter provides the following information:
•Overview on page 1-1
•Advantages of ISL Trunking on page 1-1
•Trunking Groups, Ports and Masters on page 1-3
Overview
Interswitch Link (ISL) Trunking is an optionally licensed product available on the FC Entry Switch
8B, FC Switch 8B, and FC 16B switches with Fabric OS version 3.0.1b or later. ISL Trunking is
managed using telnet commands or the Web Tools interface.
The ISL Trunking feature allows up to four ISLs, connections between two switches through an
Expansion Port (E_Port), to merge logically into a single link. When using ISL Trunking to
aggregate bandwidth of up to four ports, the throughput of the ISLs between switches in a fabric is
quadrupled. For example, at 2 Gb/Sec speeds, ISL Trunking delivers ISL throughput of up to 8
Gb/Sec.
ISL Trunking also supports high-bandwidth, large-scale Storage Area Networks (SANs) which
include core switches. The primary task of ISL Trunking is to route data and edge switches that
aggregate connections to servers and storage. ISL Trunking simplifies network design and reduces
the cost of storage management by optimizing bandwidth utilization and enabling load sharing of
traffic at the frame-level.
For a list of frequently asked questions about the ISL Trunking Feature, refer to Frequently Asked
Questions about ISL Trunking on page 3-4.
Advantages of ISL Trunking
The ISL Trunking feature enhances switch to switch performance in Storage Area Networks while
simplifying management and improving reliability. Advantages of the ISL Trunking feature
include:
•Combining up to four ISLs into a single logical ISL
•Load sharing traffic across all ISLs in a trunk
•Maintaining in-order delivery of frames
•Avoiding rerouting if one of the server links between two switches fails
•Simplifying management by implementing fewer ISLs

1-2 ISL Trunking User’s Guide
Introducing ISL Trunking
1
Routing without the ISL Trunking Feature
Prior to the implementation of the ISL Trunking feature, device-level load sharing was done
through Fibre Channel networks that created ISLs and operated with the Fibre Channel Shortest
Path First (FSPF) routing protocol. The protocol established and communicated the shortest paths
for data to be carried from source to destination. Load sharing multiple ISLs to connect two
switches was established by a round robin algorithm that assigned the next available ISL as part of
the link to connect a Host Bus Adapter (HBA) and storage. Depending on the fabric event
sequences, multiple HBAs shared an individual ISL. This type of load sharing sometimes caused
the fabric to have congested input/output traffic over the ISLs connecting two switches.
Although FSPF compliant switches ensure fixed routing paths, and guarantee that all frames are
delivered in order, congestion occurs if the aggregation of the stream exceeds the capacity of one of
the ISLs in the path.
For example, Figure 1-1 shows four untrunked ISLs with a maximum capacity of 2Gb/Sec each, for
a maximum throughput of 8Gb/Sec. Due to traffic that is not trunked, the throughput of the four
ISLs is: 1Gb/Sec + 1.5Gb/Sec +.5G + 1Gb/Sec + 1Gb/Sec, giving a total of only 5Gb/Sec, because
two 2Gb/Sec data streams are competing for the same path.
Figure 1-1 Routing without the ISL Trunking Feature
Routing with the ISL Trunking Feature
ISL Trunking ensures that all links are used efficiently, eliminating congestion on one link, while
distributing the load of the links. This feature is designed to significantly reduce traffic congestion.
As shown in Figure 1-2, four ISLs are combined into a single logical ISL with a total capacity of
8Gb/Sec.
The ISL Trunking feature distributes workload across all ISLs in a trunk. Each incoming frame is
sent across the first available ISL. As a result, transient workload peaks for one system or
application are much less likely to impact the performance of other parts of SAN fabric. Because
the full bandwidth of each physical link is available, bandwidth is efficiently allocated.

ISL Trunking User’s Guide 1-3
Introducing ISL Trunking 1
In Figure 1-2, four ISLs provide 8Gb/Sec of total throughput. With the implementation of ISL
Trunking, bandwidth is shared across the trunked ISLs, permitting a total throughput of 2Gb/Sec. +
1.5Gb/Sec + 0.5Gb/Sec + 1 Gb/Sec + 2Gb/Sec, or 7Gb/Sec. Because the trunk aggregates the four
individual paths into one and preserves in-order deliver of frames, the total throughput is increased
compared to a non-trunked group of ISLs.
Figure 1-2 Routing with the ISL Trunking Feature
Trunking Groups, Ports and Masters
ISL Trunking dynamically performs load sharing, at the frame level, across a set of available links
between two adjacent switches to establish a trunking group. Ports that belong to a trunking group
are called trunking ports. One port is used to assign traffic for the group, and is referred to as the
trunking master.
Trunking Groups
A trunking group is identified by the trunking master that represents the entire group. The rest of
the group members are referred to as slave links that help the trunking master direct traffic across
ISLs, allowing efficient and balanced in-order communication.
Trunking Ports
Trunking ports in a trunking group must meet the following criteria:
•Port must be configured as E_ports.
•Ports must reside in the same contiguous four-port groups. For example: 0-3, 4-7, 8-11, 12-15.
•Ports must be set to run at the 2G speed.
•The cable difference between all ports in a trunking group must be less than 400 meters, and
should be kept to 30 meters or less within a trunk to ensure optimal performance and
bandwidth utilization.
Note: Short Wave Length (SWL) and Long Wave Length (LWL) fiber optics can be intermixed
within a trunking group.

1-4 ISL Trunking User’s Guide
Introducing ISL Trunking
1
Trunking Masters
The trunking master implicitly defines the trunking group. All ports with the same master are
considered to be part of the same group. Each trunking group includes a single trunking master and
from 1 to 3 trunking slave links. The first ISL found in any trunking group is assigned to be the
trunking master, also known as the principal ISL. After the trunking group is fully established, all
data packets intended for transmission across the trunk are dynamically distributed at the frame
level across the ISLs in the trunking group, while preserving in-order delivery.

ISL Trunking User’s Guide 2-1
Chapter
2
Installing ISL Trunking
Overview
Installing the ISL Trunking feature involves activating a license for each switch you want to enable
for trunking. After the license is activated, ISL Trunking is automatically invoked as ISLs are
added between two 2Gbit/Sec switches. A license may have been installed in the switch at the
factory. If not, contact your switch supplier to obtain a license key.
The ISL Trunking feature requires an HP Surestore FC Switch with Fabric OS version 3.0.1b or
later. A Trunking license can be installed using either telnet or Web Tools.
Installing ISL Trunking through Telnet
To use telnet to log on to the ISL Trunking feature, do the following:
1. From a command prompt screen, use the telnet command to log onto the switch (see the user’s
guide provided with the hardware for details), using an account that has administrative
privileges.
2. Determine whether a ISL Trunking license is already installed on the switch, type
licenseShow on the telnet command line.
A list displays of all the licenses currently installed on the switch. For example:
admin> licenseShow
1A1AaAaaaAAAA1a:
Web license
Zoning license
SES license
Trunking license
If the Trunking license is not included in the list, or is incorrect, continue with step [3].
3. Enter the following on the command line:
licenseAdd “key”
where “key” is the license key provided to you, enclosed in double quotes. The license key is
case-sensitive and must be entered exactly as given.
4. Verify the license was added by entering the following on the command line:
licenseShow
If the ISL Trunking license is listed, the feature is installed and immediately available.
If the license is not listed, repeat step [3].
5. Disable the switch by entering the following command:

2-2 ISL Trunking User’s Guide
Installing ISL Trunking
2
switchdisable
6. Enable the switch by entering the following command:
switchenable
Installing ISL Trunking through Web Tools
To enter the ISL Trunking license key using the Web Tool user interface, do the following
1. Launch the Web browser, enter the switch name or IP address in the Location/Address field,
and press Enter.
Web Tools launches, displaying the Fabric View.
2. Click the Admin View button on the relevant switch panel.
The logon window displays.
3. Enter a logon name and password with administrative privileges and press Enter.
The Switch Admin view displays.
4. Select the License Admin tab, enter the license key in the License Key field, and click Add.
The Trunking feature is available as soon as the license key is added.
5. Select Switch Settings tab, disable the switch by selecting Disable.
6. Enable the switch by selecting Enable.

ISL Trunking User’s Guide 3-1
Chapter
3
Using ISL Trunking
This chapter provides the following information:
•Overview on page 3-1
•Administering ISL Trunking on page 3-1
•Frequently Asked Questions about ISL Trunking on page 3-4
Overview
The ISL Trunking feature is managed by performing some administration tasks. These tasks
include: enabling or disabling the trunking, enabling and disabling ports of a switch, setting the
speed of a port, and debugging a trunking link failure.
Administering ISL Trunking
The ISL Trunking feature is administered using telnet commands, or through Web Tools (an
optionally licensed product). You can also attach another cable to an additional port within a trunk
group quad to establish a trunking group.

3-2 ISL Trunking User’s Guide
Using ISL Trunking
3
ISL Trunking Telnet Commands
The following table shows the telnet commands used to manage the ISL Trunking feature.
For detailed information on how to use these commands, refer to the Fabric OS Reference Guide.
Table 3-1 ISL Trunking Telnet Commands
Telnet Command Description Example
portCfgTrunkport Use this command to
configure a port to be
enabled or disabled for
ISL Trunking.
To enable port 5 for ISL Trunking,
enter:
portCfgTrunkport 5, 1
To disable port 5 for ISL Trunking,
enter:
portCfgTrunkport 5, 0
switchCfgTrunk Use this command to
enable or disable
trunking on all ports of a
switch.
To enable ISL Trunking on all ports of
a switch, enter:
switchCfgTrunk 1
To disable ISL Trunking on all ports
of a switch, enter:
switchCfgTrunk 0
trunkDebug Use this command to
debug a trunk link
failure.
To debug ports 1 and 2, enter:
trunkDebug 1, 2
trunkshow Use this command to
display ISL Trunking
membership
information.
To display ISL Trunking membership
information about users, enter:
trunkshow

Brocade Trunking User’s Guide 3-3
Using ISL Trunking 3
Using Web Tools for ISL Trunking
Use Web Tools to view and modify ISL Trunking options through the Trunk Information Tab and
the Port Settings Tab on the Switch Administration interface. For information on how to install and
use Web Tools for the ISL Trunking feature, refer to the Web Tools User’s Guide.
Use the Web Tools Trunk Information tab to view a summary of trunk groups and associated master
and member ports. Table 3-2 describes the headings displayed from the Trunk Information tab.
The following table describes the headings and the tasks you can perform using the Web Tools Port
Setting tab.
Note: ISL Trunking ports always must operate at 2Gb/Sec, setting the speed to 1Gb/Sec prevents
a port from participating in a trunk.
Table 3-2 Trunk Information Tab Description
Trunk Information Tab Description
Trunk Group A numerical number is displayed.
Master Port The associated master port for the group is
displayed.
Member Ports Shows the member ports associated with the
group, separated by a comma.
Table 3-3 Port Setting Tab Features
Port Setting Tab Features Description
Port Number Each port is assigned a number. The port
numbers are displayed under this heading.
Trunking Enable:Disable This allows you to enable or disable ISL
Trunking on a per port basis.
Port Enable:Disable Use this to enable or disable a port.
Port Speed Use this to set the speed of the port to 2Gb/Sec.

3-4 ISL Trunking User’s Guide
Using ISL Trunking
3
Frequently Asked Questions about ISL Trunking
The following table lists Frequently Asked Questions about the ISL Trunking feature:
Table 3-4 Frequently Asked Questions about ISL Trunking
Frequently Asked Questions Answers
Does ISL Trunking replace Dense Wavelength
Digital Multiplexing (DWDM)? No. DWDM is a ring, and if a failure occurs it reroutes the allocated wavelength over alternate
routes, and therefore changes the effective
cable lengths.
What happens if an ISL in the trunk slave port
fails? If one of the trunk slave ports fails, the logical ISL stays up, however, its capacity is reduced
by 2Gb/Sec, and no route failure or re-routing
of traffic occurs.
What happens if a trunk master fails? If a trunk master fails, the ISL goes down, and
FSFP perceives a momentary route failure. The
trunk immediately re-forms without the failed
ISL, and traffic resumes over the re-formed
trunk with capacity reduced by 2Gb/sec.
Are trunks automatically established when the
trunking feature is enabled? Yes. Trunks are automatically established on available ports when the trunking feature is
enabled.
Is it possible to have more than one trunk
between a pair of switches? Yes.
Is there a limit on the number of trunks I can
have on one switch? No.
Is there a limit on the number of trunks I can
have between a pair of switches? No.
Is it possible to trunk between a switch and an
edge devices host or storage? No.
Should port statistics be the same across all
participating ISLs within a trunk? Not necessarily, it depends on the payload variations at the frame level. While optimal
bandwidth utilization is the goal of the ISL
Trunking feature, traffic might not be
distributed exactly the same across all ISL links
within a trunk.

ISL Trunking User’s Guide Glossary-1
Glossary
8b/10b
Encoding An encoding scheme that converts each 8-bit byte into 10 bits. Used to balance
ones and zeros in high-speed transports.
Address
Identifier A 24-bit or 8-bit value used to identify the source or destination of a frame.
Advanced
Performance
Monitoring
A software product that provides error and performance information to the
administrator and end user for use in storage management.
AL_PA Arbitrated Loop Physical Address; a unique 8-bit value assigned during loop
initialization to a port in an arbitrated loop.
Alias Address
Identifier An address identifier recognized by a port in addition to its standard identifier. An
alias address identifier may be shared by multiple ports.
Alias AL_PA An AL_PA value recognized by an L_Port in addition to the AL_PA assigned to
the port. See also AL_PA.
Alias Server A fabric software facility that supports multicast group management.
ANSI American National Standards Institute; the governing body for Fibre Channel
standards in the U.S.A.
API Application Programming Interface; defined protocol that allows applications to
interface with a set of services.
Arbitrated
Loop A shared 100 MBps Fibre Channel transport structured as a loop. Can support up
to 126 devices and one fabric attachment. See also Topology.
ASIC Application Specific Integrated Circuit.
ATM Asynchronous Transfer Mode; a transport used for transmitting data over LANs
or WANs that transmit fixed-length units of data. Provides any-to-any
connectivity, and allows nodes to transmit simultaneously.
AW_TOV Arbitration Wait Time-out Value; the minimum time an arbitrating L_Port waits
for a response before beginning loop initialization.
Bandwidth The total transmission capacity of a cable, link, or system. Usually measured in
bps (bits per second). May also refer to the range of transmission frequencies
available to a network. See also Throughput.
BB_Credit Buffer-to-buffer credit; the number of frames that can be transmitted to a directly
connected recipient or within an arbitrated loop. Determined by the number of
receive buffers available. See also Buffer-to-buffer Flow Control, EE_Credit.
Beginning
Running
Disparity
The disparity at the transmitter or receiver when the special character associated
with an ordered set is encoded or decoded. See also Disparity.

Glossary-2 ISL Trunking User’s Guide
BER Bit Error Rate; the rate at which bits are expected to be received in error.
Expressed as the ratio of error bits to total bits transmitted. See also Error.
Block As applies to Fibre Channel, upper-level application data that is transferred in a
single sequence.
Broadcast The transmission of data from a single source to all devices in the fabric,
regardless of zoning. See also Multicast, Unicast.
Buffer-to-buffer
Flow Control Management of the frame transmission rate in either a point-to-point topology or
in an arbitrated loop. See also BB_Credit.
Cascade Two or more interconnected Fibre Channel switches. For HP switches, a
maximum of seven hops is recommended (no path longer than eight switches).
See also Fabric, ISL.
Chassis The metal frame in which the switch and switch components are mounted.
Circuit An established communication path between two ports. Consists of two virtual
circuits capable of transmitting in opposite directions. See also Link.
Class 1 Service that provides a dedicated connection between two ports (also called
connection-oriented service), with notification of delivery or nondelivery.
Class 2 Service that provides multiplex and connectionless frame switching service
between two ports, with notification of delivery or nondelivery.
Class 3 Service that provides a connectionless frame switching service between two ports,
without notification of delivery or nondelivery of data. Can also be used to
provide a multicast connection between the originator and recipients, with
notification of delivery or nondelivery.
Class F Connectionless service for control traffic between switches, with notification of
delivery or nondelivery of data between the E_Ports.
Class of
Service A specified set of delivery characteristics and attributes for frame delivery.
Comma A unique pattern (either 1100000 or 0011111) used in 8B/10B encoding to specify
character alignment within a data stream. See also K28.5.
Community
(SNMP) A relationship between a group of SNMP managers and an SNMP agent, in which
authentication, access control, and proxy characteristics are defined. See also
SNMP.
CRC Cyclic Redundancy Check; a check for transmission errors included in every data
frame.
Credit As applies to Fibre Channel, the number of receive buffers available for
transmission of frames between ports. See also BB_Credit, EE_Credit.
Cut-through A switching technique that allows the route for a frame to be selected as soon as
the destination address is received. See also Route.
Data Word Type of transmission word that occurs within frames. The frame header, data
field, and CRC all consist of data words. See also Frame, Ordered set,
Transmission Word.
Defined Zone
Configuration The set of all zone objects defined in the fabric. May include multiple zone
configurations. See also Enabled Configuration, Zone Configuration.