Note

The documentation set for this product strives to use bias-free language. For purposes of this documentation set, bias-free is defined as language that does not imply discrimination based on age, disability, gender, racial identity, ethnic identity, sexual orientation, socioeconomic status, and intersectionality. Exceptions may be present in the documentation due to language that is hardcoded in the user interfaces of the product software, language used based on standards documentation, or language that is used by a referenced third-party product.

Horizontal stacking, also referred to as long-reach stacking, allows you to stack between two to four IE 5000 switches that are far apart, potentially up to a few kilometers. Horizontal stacking works by converting two of the TenGigabit Ethernet ports on the front of the IE5000 into special stacking ports. The special stacking ports interconnect the switches, forming the communication backbone of the stack. Switches can be stacked across multiple cell/area zone locations, and even across multiple buildings in a customer environment. Horizontal stacking provides resiliency and optimal convergence in industrial Ethernet networks.

In a stack, all switches appear as a single logical switch with a single IP address. Benefits of stacking include ease of management due to fewer stand-alone devices, increased port density, increased redundancy, and flexibility to add devices as required. All manageable entities (for example, Ethernet interfaces and VLANs) on all physical switches can be configured and managed from the logical switch. In a Layer 2 network, the logical switch appears as a single spanning-tree entity.

Horizontal stacking is supported on IE 5000 switch model IE-5000-12S12P-10G. Any one or two of the four 10 Gigabit Ethernet uplink ports on this switch can connect to another IE-5000-12S12P-10G switch in a different location to form a stack. You configure the 10G uplink ports as stack ports using the Command Line Interface (CLI). With two stack ports configured, the physical members of the stack form a ring, providing a built-in redundant data path for each member of the stack.

The following figure shows an example of stacked IE 5000 switches connecting multiple cell/area zones in a manufacturing network. The example does not show all possible connections.

Data path redundancy is built into the stacking architecture because there are two physical paths between any two stack members (represented by the green cables in the figure). Stacking increases Ethernet switch availability by providing redundancy for both the physical switch and the uplink. Because different physical switches connect to the upstream network, losing one switch or one uplink interface does not prevent connectivity to the network. Since the logical switch has multiple uplinks, the logical switch still has network connectivity because at least one uplink is still active.

• All interface configurations are lost when changing between non-stack mode and stack mode on a switch, because the interface names change from slot/port in non-stack mode to switch/slot/port in stack mode. For example, GigabitEthernet1/1 changes to GigabitEthernet1/1/1 when the switch is configured for stack mode.

• When horizontal stacking is enabled and the switch is reloaded, due to the interface name change, configuration on the interface is lost. We recommend that you use the VLAN interface for management access, which is not affected by this change.

• When you hot swap a horizontal stacking switch, if you reload a stack member with a 1G SFP inserted on a 10G interface, the interface configuration disappears. To avoid this problem, reload the entire stack if IOS version 15.2(8)E5 or earlier release in use. This limitation is fixed in 15.2(8)E6 image or higher.

• The following features are not supported in stack mode, and the CLI for these features is not visible when the switch is in stack mode:

  • Device Manager (DM)

  • Common Industrial Protocol (CIP)

  • Layer 2 Network Address Translation (L2 NAT)

  • Parallel Redundancy Protocol (PRP)

  • PROFINET and Media Redundancy Protocol (MRP)

    When the switch is in stack mode, it does not support MRP in either PROFINET MRP mode or MRP CLI mode.

  • Any other features that are not listed in Feature Support in Stack Mode.

  Note

  There are many non-IoT features that are not supported in stack mode. These features are not disabled and the CLI for these features is also available. However, if you attempt to use these features in stack mode, they may not function as intended. We recommend that you use only the features listed in Feature Support in Stack Mode. with horizontal stacking.

• Redundancy protocols converge more slowly on a stacked switch due to stacking on fiber interfaces. Refer to individual protocol configuration guides for recommendations. It is recommended to restrict Resilient Ethernet Protocol (REP) to 8 segments with 24 switches per segment.

• A maximum of two 10G interfaces can be converted to stack ports. After these interfaces are in stack mode, they are not available for normal network operation and do not appear in an interface listing such as show interface status , show ip interface brief , and so on.

• Converting a network port to or from a stack port requires a switch reload to take effect.

• If a saved configuration is applied on a stack port that was a network port in the previous reload, the configuration will fail.

• When no 10G network port is set as stack port, IE 5000 runs in standalone mode. In standalone mode, the switch cannot be stacked with another stack-enabled or standalone IE 5000 switch. IoT protocols can be configured in standalone mode.

• No features have been modified for stacking.

• There is no new SDM template and no change in the existing SDM template options.

• Stack convergence will be slower than 500 ms due to stacking on fiber interfaces.

• PAgP cannot be enabled on cross-stack EtherChannels.

• When connecting stacked switches, ensure that hstack port1 on one switch is connected to hstack port1 of the other switch, and hstack port2 is connected to hstack port2 of the other switch.

By default, 10G interfaces are configured to operate as network ports.

To display the stacking status of the 10G ports, enter the following show command:

Switch#show switch hstack-ports

The command output shows:

• All the 10G ports available on the master and all members that are capable of horizontal stacking.

• The stack port number—1 or 2, corresponding to any 10G port that has been converted to a horizontal stack port.

• Operational status of the 10G port—Stack Port or N/W (network (uplink) port).

• The status of the 10G port at the next reload.

• The media type.

Any 10G port that is configured as a horizontal stack port can be converted back to a normal uplink port. This will be effective only after the next reload.

The following example shows output for a four-member full ring horizontal stack on the IE 5000:

The following example shows the output when Te1/1/27 and Te2/1/28 are converted back to N/W ports, but the switches have not been reloaded:

To display the role of a stack port, use the show switch command:

The preceding example shows that member 4 is the master. All stack members have a stack priority of 1 (the default).

Possible stack member states are:

• Ready—Member is up and part of the stack.

• Progressing—Member is booting up.

• Mismatch—A hardware or software mismatch is preventing the member from fully joining.

• Provisioned—Member has been configured, but is not part of the stack and has never been part of the stack.

• Removed—Member is not currently powered on or was removed from the stack.

The MAC address of the master is used as the MAC address of the logical stack. This is the base MAC address from the master, and is used for all IP communications, as well as Cisco Discovery Protocol data exchange and Spanning Tree Protocol.

To view other operational aspects of the stack, these commands are useful:

• show version —View the Cisco IOS Software version of all stack members. Useful if there is a mismatch.

• show switch neighbors —View which members are connected to which stack ports.

• show switch stack-ring speed —View details of the stack ring, for example:

Switch#show
 switch stack-ring speed
Stack Ring Speed : 10G
Stack Ring Configuration: Full
Stack Ring Protocol : FlexStack
Switch#

This example shows how to convert two 10G uplink ports from network ports to stack ports:

Switch#config t
Enter configuration commands, one per line.  End with CNTL/Z.
Switch(config)#switch 1 hstack-port 1 TenGigabitEthernet 1/25
Do you want to continue?[confirm]
New port setting will be effective after next reload
Switch(config)#switch 1 hstack-port 2 TenGigabitEthernet 1/26
Do you want to continue?[confirm]
New port setting will be effective after next reload
Te1/25 will be assigned as horizontal stack port 1
Te1/26 will be assigned as horizontal stack port 2

This example shows how to convert a stack port to a network port:

Switch(config)#no switch 1 hstack-port 1
 
Do you want to continue?[confirm]
New port setting will be effective after next reload

For Cisco Industrial Ethernet 5000 Series Switches documentation, see http://www.cisco.com/go/ie5000 .