H3C S5150-EI Series User manual

H3C S5150-EI Switch Series
IRF Configuration Guide
New H3C Technologies Co., Ltd.
http://www.h3c.com.hk
Software version: Release 510x
Document version: 6W101-20171222

Copyright © 2016-2017, New H3C Technologies Co., Ltd. and its licensors
All rights reserved
No part of this manual may be reproduced or transmitted in any form or by any means without prior written
consent of New H3C Technologies Co., Ltd.
Trademarks
H3C, , H3CS, H3CIE, H3CNE,Aolynk, , H3Care, , IRF, NetPilot, Netflow, SecEngine,
SecPath, SecCenter, SecBlade, Comware, ITCMM and HUASAN are trademarks of New H3C Technologies
Co., Ltd.
All other trademarks that may be mentioned in this manual are the property of their respective owners
Notice
The information in this document is subject to change without notice. Every effort has been made in the
preparation of this document to ensure accuracy of the contents, but all statements, information, and
recommendations in this document do not constitute the warranty of any kind, express or implied.

Preface
This configuration guide describes how to set up an IRF fabric of multiple S5150-EI switches,
including:
•Plan the switch roles in the IRF fabric.
•Connect the IRF links.
•Detect IRF splits and maintain the IRF fabric.
This preface includes the following topics about the documentation:
•Audience
•Conventions
•Obtaining documentation
•Technical support
•Documentation feedback
Audience
This documentation is intended for:
•Network planners.
•Field technical support and servicing engineers.
•Network administrators.
Conventions
The following information describes the conventions used in the documentation.
Command conventions
Convention Description
Boldface Bold text represents commands and keywords that you enter literally as shown.
Italic Italic text represents arguments that you replace with actual values.
[ ] Square brackets enclose syntax choices (keywords or arguments) that are optional.
{ x | y | ... }
Braces enclose a set of required syntax choices separated by vertical bars, from which
you select one.
[ x | y | ... ]
Square brackets enclose a set of optional syntax choices separated by vertical bars,
from which you select one or none.
{ x | y | ... } *
Asterisk marked braces enclose a set of required syntax choices separated by vertical
bars, from which you select a minimum of one.
[ x | y | ... ] *
Asterisk marked square brackets enclose optional syntax choices separated by vertical
bars, from which you select one choice, multiple choices, or none.
&<1-n> The argument or keyword and argument combination before the ampersand (&) sign
can be entered 1 to n times.
# A line that starts with a pound (#) sign is comments.

GUI conventions
Convention Description
Boldface Window names, button names, field names, and menu items are in Boldface. For
example, the New User window opens; click OK.
> Multi-level menus are separated by angle brackets. For example, File > Create >
Folder.
Symbols
Convention Description
WARNING! An alert that calls attention to important information that if not understood or followed
can result in personal injury.
CAUTION: An alert that calls attention to important information that if not understood or followed
can result in data loss, data corruption, or damage to hardware or software.
IMPORTANT: An alert that calls attention to essential information.
NOTE: An alert that contains additional or supplementary information.
TIP: An alert that provides helpful information.
Network topology icons
Convention Description
Represents a generic network device, such as a router, switch, or firewall.
Represents a routing-capable device, such as a router or Layer 3 switch.
Represents a generic switch, such as a Layer 2 or Layer 3 switch, or a router that
supports Layer 2 forwarding and other Layer 2 features.
Represents an access controller, a unified wired-WLAN module, or the access
controller engine on a unified wired-WLAN switch.
Represents an access point.
Represents a wireless terminator unit.
Represents a wireless terminator.
Represents a mesh access point.
Represents omnidirectional signals.
Represents directional signals.
Represents a security product, such as a firewall, UTM, multiservice security
gateway, or load balancing device.
T
T
T
T





Convention Description
Represents a security module, such as a firewall, load balancing, NetStream, SSL
VPN, IPS, or ACG module.
Examples provided in this document
Examples in this document might use devices that differ from your device in hardware model,
configuration, or software version. It is normal that the port numbers, sample output, screenshots,
and other information in the examples differ from what you have on your device.
Obtaining documentation
To access the most up-to-date H3C product documentation, go to the H3C website at
http://www.h3c.com.hk/
To obtain information about installation, configuration, and maintenance, click
http://www.h3c.com.hk/Technical_Documents
To obtain software version information such as release notes, click
http://www.h3c.com.hk/Software_Download
Technical support
[e-mail]
http://www.h3c.com.hk/
Documentation feedback
You can e-mail your comments about product documentation to [e-mail].
We appreciate your comments.

i
Contents
Setting up an IRF fabric·····································································1
Overview··································································································································1
Network topology ················································································································2
Basic concepts ···················································································································2
Interface naming conventions ································································································4
File system naming conventions·····························································································4
Configuration synchronization································································································5
Loop elimination mechanism··································································································5
Master election ···················································································································6
Multi-active handling procedure······························································································6
MAD mechanisms ···············································································································7
Hardware compatibility··············································································································12
General restrictions and configuration guidelines ············································································12
Software requirements ·······································································································12
IRF physical interface requirements·······················································································12
Connecting IRF ports ·········································································································13
Configuration backup ·········································································································13
Setup and configuration task list··································································································13
Planning the IRF fabric setup······································································································14
Assigning a member ID to each IRF member device········································································15
Specifying a priority for each member device ·················································································15
Connecting IRF physical interfaces······························································································16
Binding physical interfaces to IRF ports ························································································16
Accessing the IRF fabric············································································································18
Bulk-configuring basic IRF settings for a member device··································································18
Configuring a member device description······················································································19
Configuring IRF link load sharing mode ························································································19
Configuring the global load sharing mode···············································································20
Configuring a port-specific load sharing mode ·········································································20
Configuring IRF bridge MAC persistence ······················································································20
Enabling software auto-update for software image synchronization·····················································21
Configuration prerequisites··································································································22
Configuration procedure ·····································································································22
Setting the IRF link down report delay ··························································································22
Configuring MAD ·····················································································································23
Configuring LACP MAD······································································································23
Configuring BFD MAD········································································································24
Configuring ARP MAD········································································································26
Configuring ND MAD··········································································································27
Excluding a port from the shutdown action upon detection of multi-active collision···························28
Recovering an IRF fabric···········································································································29
Displaying and maintaining an IRF fabric ······················································································30
Configuration examples·············································································································31
LACP MAD-enabled IRF configuration example·······································································31
BFD MAD-enabled IRF configuration example·········································································35
ARP MAD-enabled IRF configuration example·········································································39
ND MAD-enabled IRF configuration example ··········································································43
Index···························································································49

1
Setting up an IRF fabric
Overview
The Intelligent Resilient Framework (IRF) technology virtualizes multiple physical devices at the
same layer into one virtual fabric to provide data center class availability and scalability. IRF
virtualization technology offers processing power, interaction, unified management, and
uninterrupted maintenance of multiple devices.
Figure 1 shows an IRF fabric that has two devices, which appear as a single node to the upper-layer
and lower-layer devices.
Figure 1 IRF application scenario
IRF provides the following benefits:
•Simplified topology and easy management—An IRF fabric appears as one node and is
accessible at a single IP address on the network. You can use this IP address to log in at any
member device to manage all the members of the IRF fabric. In addition, you do not need to run
the spanning tree feature among the IRF members.
•1:N redundancy—In an IRF fabric, one member acts as the master to manage and control the
entire IRF fabric. All the other members process services while backing up the master. When
the master fails, all the other member devices elect a new master from among them to take over
without interrupting services.
•IRF link aggregation—You can assign several physical links between neighboring members to
their IRF ports to create a load-balanced aggregate IRF connection with redundancy.
•Multichassis link aggregation—You can use the Ethernet link aggregation feature to
aggregate the physical links between the IRF fabric and its upstream or downstream devices
across the IRF members.
•Network scalability and resiliency—Processing capacity of an IRF fabric equals the total
processing capacities of all the members. You can increase ports, network bandwidth, and
processing capacity of an IRF fabric simply by adding member devices without changing the
network topology.

2
Network topology
An IRF fabric can use a daisy-chain or ring topology. IRF does not support the full mesh topology. For
information about connecting IRF member devices, see "Connecting IRF physical interfaces."
Basic concepts
IRF member roles
IRF uses two member roles: masterand standby (called subordinate throughout the documentation).
When devices form an IRF fabric, they elect a master to manage and control the IRF fabric, and all
the other devices back up the master. When the master device fails, the other devices automatically
elect a new master. For more information about master election, see "Master election."
IRF member ID
An IRF fabric uses member IDs to uniquely identify and manage its members. This member ID
information is included as the first part of interface numbers and file paths to uniquely identify
interfaces and files in an IRF fabric. For more information about interface and file path naming, see
"Interface naming conventions" and "File system naming conventions."
Two devices cannot form an IRF fabric if they use the same member ID.Adevice cannot join an IRF
fabric if its member ID has been used in the fabric.
IRF port
An IRF port is a logical interface that connects IRF member devices. Every IRF-capable device has
two IRF ports. The IRF ports are named IRF-port n/1 and IRF-port n/2, where nis the member ID of
the switch. The two IRF ports are referred to as IRF-port 1 and IRF-port 2 in this book.
To use an IRF port, you must bind a minimum of one physical interface to it. The physical interfaces
assigned to an IRF port automatically form an aggregate IRF link. An IRF port goes down when all its
IRF physical interfaces are down.
IRF physical interface
IRF physical interfaces connect IRF member devices and must be bound to an IRF port. They
forward traffic between member devices, including IRF protocol packets and data packets that must
travel across IRF member devices.
For more information about physical interfaces that can be used for IRF links, see "IRF physical
interface requirements."
MAD
An IRF link failure causes an IRF fabric to split in two IRF fabrics operating with the same Layer 3
settings, including the same IP address. To avoid IP address collision and network problems, IRF
uses multi-active detection (MAD) mechanisms to detect the presence of multiple identical IRF
fabrics, handle collisions, and recover from faults.
IRF domain ID
One IRF fabric forms one IRF domain. IRF uses IRF domain IDs to uniquely identify IRF fabrics and
prevent IRF fabrics from interfering with one another.
As shown in Figure 2, IRF fabric 1 contains Device Aand Device B, and IRF fabric 2 contains Device
C and Device D. Both fabrics use the LACP aggregate links between them for MAD. When a
member device receives an extended LACPDU for MAD, it checks the domain ID to see whether the
packet is from the local IRF fabric. Then, the device can handle the packet correctly.

3
Figure 2 A network that contains two IRF domains
IRF split
IRF split occurs when an IRF fabric breaks up into multiple IRF fabrics because of IRF link failures,
as shown in Figure 3. The split IRF fabrics operate with the same IP address. IRF split causes
routing and forwarding problems on the network. To quickly detect a multi-active collision, configure
a minimum of one MAD mechanism (see "Configuring MAD").
Figure 3 IRF split
IRF merge
IRF merge occurs when two split IRF fabrics reunite or when two independent IRFfabrics are united,
as shown in Figure 4.
Figure 4 IRF merge
Device A Device B
IRF fabric 1
(domain 10)
IRF link
Core network
IRF fabric 2
(domain 20)
IRF link
Device C Device D
Access network

4
Member priority
Member priority determines the possibility of a member device to be elected the master. A member
with higher priority is more likely to be elected the master.
Interface naming conventions
An interface is named in the chassis-id/slot-number/port-index format.
•chassis-id—IRF member ID of the device. This argument defaults to 1. The IRF member ID
always takes effect, whether or not the device has formed an IRF fabric with other devices. If
the device is alone, the device is regarded a one-chassis IRF fabric.
•slot-number—Slot number of the front panel. This argument is fixed at 0.
•port-index—Index of the port on the device. Port index depends on the number of ports
available on the device. To identify the index of a port, examine its port index mark on the
chassis.
For example:
•On the single-chassis IRF fabric Sysname, Ten-GigabitEthernet 1/0/1 represents the first port
on the device. Set its link type to trunk, as follows:
<Sysname> system-view
[Sysname] interface ten-gigabitethernet 1/0/1
[Sysname-Ten-GigabitEthernet1/0/1] port link-type trunk
•On the multi-chassis IRF fabric Master, Ten-GigabitEthernet 3/0/1 represents the first port on
member device 3. Set its link type to trunk, as follows:
<Master> system-view
[Master] interface ten-gigabitethernet 3/0/1
[Master-Ten-GigabitEthernet3/0/1] port link-type trunk
File system naming conventions
On a single-chassis fabric, you can use its storage device name to access its file system.
On a multichassis IRF fabric, you can use the storage device name to access the file system of the
master. To access the file system of any other member device, use the name in the
slotmember-ID#storage-device-name format.
For example:
To access the test folder under the root directory of the flash memory on the master device:
<Master> mkdir test
Creating directory flash:/test... Done.
<Master> dir
Directory of flash:
0 -rw- 43548660 Jan 01 2011 08:21:29 system.ipe
1 drw- - Jan 01 2011 00:00:30 diagfile
2 -rw- 567 Jan 02 2011 01:41:54 dsakey
3 -rw- 735 Jan 02 2011 01:42:03 hostkey
4 -rw- 36 Jan 01 2011 00:07:52 ifindex.dat
5 -rw- 0 Jan 01 2011 00:53:09 lauth.dat
6 drw- - Jan 01 2011 06:33:55 log
7 drw- - Jan 02 2000 00:00:07 logfile
8 -rw- 23724032 Jan 01 2011 00:49:47 switch-cmw710-system.bin
9 drw- - Jan 01 2000 00:00:07 seclog

5
10 -rw- 591 Jan 02 2011 01:42:03 serverkey
11 -rw- 4609 Jan 01 2011 00:07:53 startup.cfg
12 -rw- 3626 Jan 01 2011 01:51:56 startup.cfg_bak
13 -rw- 78833 Jan 01 2011 00:07:53 startup.mdb
14 drw- - Jan 01 2011 00:15:48 test
25 drw- - Jan 01 2011 04:16:53 versionInfo
1048576 KB total (889580 KB free)
To create and access the test folder under the root directory of the flash memory on member device
3:
<Master> mkdir slot3#flash:/test
Creating directory slot3#flash:/test... Done.
<Master> cd slot3#flash:/test
<Master> pwd
slot3#flash:/test
Or:
<Master> cd slot3#flash:/
<Master> mkdir test
Creating directory slot3#flash:/test... Done.
To copy the file test.ipe on the master to the root directory of the flash memory on member device 3:
# Display the current working path. In this example, the current working path is the root directory of
the flash memory on member device 3.
<Master> pwd
slot3#flash:
# Change the current working path to the root directory of the flash memory on the master device.
<Master> cd flash:/
<Master> pwd
flash:
# Copy the file to member device 3.
<Master> copy test.ipe slot3#flash:/
Copy flash:/test.ipe to slot3#flash:/test.ipe?[Y/N]:y
Copying file flash:/test.ipe to slot3#flash:/test.ipe... Done.
For more information about storage device naming conventions, see Fundamentals Configuration
Guide.
Configuration synchronization
IRF uses a strict running-configuration synchronization mechanism. In an IRF fabric, all devices
obtain and run the running configuration of the master. Configuration changes are automatically
propagated from the master to the remaining devices. The configuration files of these devices are
retained, but the files do not take effect. The devices use their own startup configuration files only
after they are removed from the IRF fabric.
For more information about configuration management, see Fundamentals Configuration Guide.
Loop elimination mechanism
Loop control protocols such as the spanning tree feature cannot be configured on IRF physical
interfaces. However, IRF has its own mechanism to eliminate loops. Before an IRF member device

6
forwards a packet, it identifies whether loops exist on the forwarding path based on the source and
destination physical interfaces and the IRF topology. If a loop exists, the device discards the packet
on the source interface of the looped path. This loop elimination mechanism will drop a large number
of broadcast packets on the IRF physical interfaces. When you use SNMP tools, do not monitor
packet forwarding on the IRF physical interfaces to reduce SNMP notifications of packet drops.
Master election
Master election occurs each time the IRF fabric topology changes in the following situations:
•The IRF fabric is established.
•The master device fails or is removed.
•The IRF fabric splits.
•Independent IRF fabrics merge.
NOTE:
Master election does not occur when two split IRF fabrics merge. All member devices in the
Recovery-state IRF fabric automatically reboot tojoin the active IRF fabric as subordinate members.
The master device of the active IRF fabric is the master device of the merged IRF fabric.
Master election selects a master in descending order:
1. Current master, even if a new member has higher priority.
When an IRF fabric is being formed, all members consider themselves as the master. This rule
is skipped.
2. Member with higher priority.
3. Member with the longest system uptime.
Two members are considered to start up at the same time if the difference between their startup
times is equal to or less than 10 minutes. For these members, the next tiebreaker applies.
4. Member with the lowest CPU MAC address.
For the setup of a new IRF fabric, the subordinate devices must reboot to complete the setup after
the master election.
For an IRF merge, devices must reboot if they are in the IRF fabric that fails the master election.
Multi-active handling procedure
The multi-active handling procedure includes detection, collision handling, and failure recovery.
Detection
MAD identifies each IRF fabric with a domain ID and an active ID (the member ID of the master). If
multiple active IDs are detected in a domain, MAD determines that an IRF collision or split has
occurred.
For more information about the MAD mechanisms and their application scenarios, see "MAD
mechanisms."
Collision handling
When MAD detects a multi-active collision, it sets all IRF fabrics except one to the Recovery state.
The fabric that is not placed in Recovery state can continue to forward traffic. The Recovery-state
IRF fabrics are inactive and cannot forward traffic.
LACP MAD and BFD MAD use the following process to handle a multi-active collision:
1. Compare the number of members in each fabric.
2. Set all fabrics to the Recovery state except the one that has the most members.

7
3. Compare the member IDs of the masters if all IRF fabrics have the same number of members.
4. Set all fabrics to the Recovery state except the one that has the lowest numbered master.
5. Shut down all physical network ports in the Recovery-state fabrics except for the following
ports:
{IRF physical interfaces.
{Ports you have specified with the mad exclude interface command.
In contrast, ARP MAD and ND MAD do not compare the number of members in fabrics. These MAD
mechanisms use the following process to handle a multi-active collision:
1. Compare the member IDs of the masters in the IRF fabrics.
2. Set all fabrics to the Recovery state except the one that has the lowest numbered master.
3. Take the same action on the network ports in Recovery-state fabrics as LACP MAD and BFD
MAD.
Failure recovery
To merge two split IRF fabrics, first repair the failed IRF link and remove the IRF link failure.
•If the IRF fabric in Recovery state fails before the failure is recovered, repair the failed IRF fabric
and the failed IRF link.
•If the active IRF fabric fails before the failure is recovered, enable the inactive IRF fabric to take
over the active IRF fabric. Then, recover the MAD failure.
MAD mechanisms
IRF provides MAD mechanisms by extending LACP, BFD, ARP, and IPv6 ND. You can configure a
minimum of one MAD mechanism on an IRF fabric for prompt IRF split detection.
•Do not configure LACP MAD together withARP MAD or ND MAD, because they handle
collisions differently.
•Do not configure BFD MAD together withARP MAD or ND MAD. BFD MAD is mutually
exclusive with the spanning tree feature, butARP MAD and ND MAD require the spanning tree
feature. At the same time, BFD MAD handles collisions differently than ARPMAD and ND MAD.
Table 1 compares the MAD mechanisms and their application scenarios.
Table 1 Comparison of MAD mechanisms
MAD
mechanism Advantages Disadvantages Application scenario
LACP MAD
•Detection speed is fast.
•Does not require
MAD-dedicated physical
links or Layer 3 interfaces.
Requires an intermediate
device that supports
extended LACP for MAD.
Link aggregation is used
between the IRF fabric
and its upstream or
downstream device.
For information about
LACP, see Layer
2—LAN Switching
Configuration Guide.
BFD MAD
•Detection speed is fast.
•No intermediate device is
required.
•Intermediate device, if
used, can come from any
vendor.
•Requires MAD
dedicated physical
links and Layer 3
interfaces, which
cannot be used for
transmitting user traffic.
•If no intermediate
device is used, any two
IRF members must
have a BFD MAD link
•No special
requirements for
network scenarios.
•If no intermediate
device is used, this
mechanism is only
suitable for IRF
fabrics that have a
small number of
members that are

8
MAD
mechanism Advantages Disadvantages Application scenario
to each other.
•If an intermediate
device is used, every
IRF member must have
a BFD MAD link to the
intermediate device.
geographically
close to one
another.
For information about
BFD, see High
Availability Configuration
Guide.
ARP MAD
•No intermediate device is
required.
•Intermediate device, if
used, can come from any
vendor.
•Does not require MAD
dedicated ports.
•Detection speed is
slower than BFD MAD
and LACP MAD.
•The spanning tree
feature must be
enabled.
Spanning tree-enabled
non-link aggregation
IPv4 network scenario.
For information about
ARP, see Layer 3—IP
Services Configuration
Guide.
ND MAD
•No intermediate device is
required.
•Intermediate device, if
used, can come from any
vendor.
•Does not require MAD
dedicated ports.
•Detection speed is
slower than BFD MAD
and LACP MAD.
•The spanning tree
feature must be
enabled.
Spanning tree-enabled
non-link aggregation
IPv6 network scenario.
For information about
ND, see Layer 3—IP
Services Configuration
Guide.
LACP MAD
As shown in Figure 5, LACP MAD has the following requirements:
•Every IRF member must have a link with an intermediate device.
•All the links form a dynamic link aggregation group.
•The intermediate device must be a device that supports extended LACP for MAD.
The IRF member devices send extended LACPDUs that convey a domain ID and an active ID. The
intermediate device transparently forwards the extended LACPDUs received from one member
device to all the other member devices.
•If the domain IDs and active IDs sent by all the member devices are the same, the IRF fabric is
integrated.
•If the extended LACPDUs convey the same domain ID but different active IDs, a split has
occurred. LACP MAD handles this situation as described in "Collision handling."

9
Figure 5 LACP MAD scenario
BFD MAD
BFD MAD can work with or without an intermediate device. Figure 6 shows a typical BFD MAD
scenario that uses an intermediate device. Figure 7 shows a typical BFD MAD scenario that does not
use an intermediate device.
To use BFD MAD:
•Set up dedicated BFD MAD link between each pair of IRF member devices or between each
IRF member device and the intermediate device. Do not use the BFD MAD links for any other
purpose.
•Assign the ports connected by BFD MAD links to the same VLAN.
•Create a VLAN interface for the VLAN, and assign a MAD IP address to each member on the
VLAN interface.
NOTE:
The MAD IP addresses identify the member devices and must belong to the same subnet.
With BFD MAD, the master attempts to establish BFD sessions with other member devices by using
its MAD IP address as the source IP address.
•If the IRF fabric is integrated, only the MAD IP address of the master takes effect. The master
cannot establish a BFD session with any other member. If you execute the display bfd
session command, the state of the BFD sessions is Down.
•When the IRF fabric splits, the IP addresses of the masters in the split IRF fabrics take effect.
The masters can establish a BFD session. If you execute the display bfd session command,
the state of the BFD session between the two devices is Up.
Intermediate device
Master Subordinate
IRF
fabric
Internet
Customer
premise
network
IRF link
Common traffic path
LACP MAD traffic path
LACP-enabled dynamic
link aggregation
LACP-enabled dynamic
link aggregation

10
Figure 6 BFD MAD scenario with an intermediate device
Figure 7 BFD MAD scenario without an intermediate device
ARP MAD
ARP MAD detects multi-active collisions by using extended ARP packets that convey the IRF
domain ID and the active ID.
You can set up ARP MAD links between neighbor IRF member devices, or between each IRF
member device and an intermediate device (see Figure 8). If an intermediate device is used, you
must also run the spanning tree feature between the IRF fabric and the intermediate device.
Each IRF member compares the domain ID and the active ID in incoming extended ARP packets
with its domain ID and active ID.
•If the domain IDs are different, the extended ARP packet is from a different IRF fabric. The
device does not continue to process the packet with the MAD mechanism.
•If the domain IDs are the same, the device compares the active IDs.
{If the active IDs are different, the IRF fabric has split.
{If the active IDs are the same, the IRF fabric is integrated.

11
Figure 8 ARP MAD scenario
ND MAD
ND MAD detects multi-active collisions by using NS packets to transmit the IRF domain ID and the
active ID.
You can set up ND MAD links between neighbor IRF member devices or between each IRF member
device and an intermediate device (see Figure 9). If an intermediate device is used, you must also
run the spanning tree protocol between the IRF fabric and the intermediate device.
Each IRF member device compares the domain ID and the active ID in incoming NS packets with its
domain ID and active ID.
•If the domain IDs are different, the NS packet is from a different IRF fabric. The device does not
continue to process the packet with the MAD mechanism.
•If the domain IDs are the same, the device compares the active IDs.
{If the active IDs are different, the IRF fabric has split.
{If the active IDs are the same, the IRF fabric is integrated.
Device
Master Subordinate
IRF
fabric
Internet
Customer
premise
network
IRF link
Common traffic path
Extended ARP traffic path
STP domain (all devices
must run the spanning
tree feature)

12
Figure 9 ND MAD scenario
Hardware compatibility
An S5150-EI switch can form an IRF fabric only with devices in the same series.
General restrictions and configuration guidelines
For a successful IRF setup, follow the restrictions and guidelines in this section and the setup
procedure in "Setup and configuration task list."
Software requirements
All IRF member devices must run the same software image version. Make sure the software
auto-update feature is enabled on all member devices.
IRF physical interface requirements
Candidate IRF physical interfaces
Use the 10GBase-T Ethernet ports or SFP+ ports on the front panel of the S5150-EI switch for IRF
links.
Selecting transceiver modules and cables
When you select transceiver modules and cables, follow these restrictions and guidelines:
Device
Master Subordinate
IRF
fabric
Internet
Customer
premise
network
IRF link
Common traffic path
Extended ND traffic path
STP domain (all devices
must run the spanning
tree feature)

13
•Use Category 6A(or above) twisted-paircables to connect 10GBase-TEthernet ports in a short
distance.
•Use SFP+ DAC cables to connect SFP+ ports in a short distance.
•Use SFP+ transceiver modules and fibers to connect SFP+ ports in a long distance.
•The transceiver modules at the two ends of an IRF link must be the same type.
For more information about the transceiver modules and DAC cables, see the switch installation
guide and H3C Transceiver Modules User Guide.
NOTE:
The transceiver modules and DAC cables available for the switch are subject to change over time.
For the most up-to-date list of transceiver modules and DAC cables, contact your H3C sales
representative.
Connecting IRF ports
When you connect two neighboring IRF members, connect the physical interfaces of IRF-port 1 on
one member to the physical interfaces of IRF-port 2 on the other.
Configuration backup
As a best practice, back up the next-startup configuration file on a device before adding thedevice to
an IRF fabric as a subordinate.
A subordinate device's next-startup configuration file might be overwritten if the master and the
subordinate use the same file name for their next-startup configuration files. You can use the backup
file to restore the original configuration after removing the subordinate from the IRF fabric.
Setup and configuration task list
As a best practice, use the basic IRF setup procedure in Figure 10. Perform the tasks in this figure on
each member device.
Figure 10 Basic IRF setup flow chart
To set up an IRF fabric:
Tasks at a glance Remarks
1. (Required.) Planning the IRF fabric setup N/A
2. (Required.) Assigning a member ID to each IRF member device Perform this task on each
member device.
3. (Optional.) Specifying a priority for each member device Perform this task on one or
multiple member devices to affect
Assign the device a
member ID and a
priority Reboot the device Connect IRF
physical interfaces
Bind the physical
interfaces to IRF
ports
Save the
configuration Activate IRF ports Subordinate devices automatically reboot IRF fabric is set up

14
Tasks at a glance Remarks
the master election result.
4. (Required.) Connecting IRF physical interfaces N/A
5. (Required.) Binding physical interfaces to IRF ports
Perform this task on each
member device.
When you complete IRF port
binding and activation on all IRF
member devices, the IRF fabric is
formed.
6. (Required.) Accessing the IRF fabric
When you log in to the IRF fabric,
you are placed at the master's
CLI, where you complete
subsequent IRF settings and
configure other features for the
member devices as if they were
one device.
7. (Optional.) Bulk-configuring basic IRF settings for a member
device
Perform this task to
bulk-configure the member ID,
domain ID, priority, and IRF port
bindings for a device.
8. (Optional.) Configuring a member device description N/A
9. (Optional.) Configuring IRF link load sharing mode:
{Configuring the global load sharing mode
{Configuring a port-specific load sharing mode N/A
10. (Optional.) Configuring IRF bridge MAC persistence N/A
11. (Optional.) Enabling software auto-update for software image
synchronization
As a best practice, enable
software auto-update to ensure
system software image
synchronization.
12. (Optional.) Setting the IRF link down report delay N/A
13. (Required.) Configuring MAD:
{Configuring LACP MAD
{Configuring BFD MAD
{Configuring ARP MAD
{Configuring ND MAD
{Excluding a port from the shutdown action upon detection of
multi-active collision
MAD mechanisms are
independent of one another. You
can configure multiple MAD
mechanisms for an IRF fabric.
14. (Optional.) Recovering an IRF fabric N/A
Planning the IRF fabric setup
Consider the following items when you plan an IRF fabric:
•Hardware compatibility and restrictions.
•IRF fabric size.
•Master device.
•IRF physical interfaces.
•Member ID and priority assignment scheme.
•Fabric topology and cabling scheme.