Lenovo is open and ready for business with System x
IBM x86 products are now products of Lenovo in the U.S. and other countries. IBM will continue to host x86-related content on ibm.com until migrated to Lenovo.
Learn more about the acquisition
The Lenovo® Flex System™ EN4091 10Gb Ethernet Pass-thru offers easy connectivity of the Flex System chassis to any external network infrastructure. This unmanaged device enables direct connectivity of the compute node in the chassis to an external top-of-rack data center switch. This module can function at both 1 Gb and 10 Gb Ethernet speeds. It has fourteen internal 10 Gb links, and fourteen external 10 Gb SFP+ uplinks.
Changes in the June 1 update:
* Added TOC for web
* Updated product descriptions
* Updated product images
* Added new LC-LC cables
* Added new Active and Passive DAC cables
* Added chassis compatibility
* Updated network cabling requirements
* Updated typical configurations
* Removed withdrawn transceivers
The Lenovo® Flex System™ EN4091 10Gb Ethernet Pass-thru offers easy connectivity of the Flex System chassis to any external network infrastructure. This unmanaged device enables direct Ethernet connectivity of the compute node in the chassis to an external top-of-rack (TOR) data center switch. This module can function at both 1 Gb and 10 Gb Ethernet speeds. It has fourteen internal 1 Gb or 10 Gb links, and fourteen external 1 Gb or 10 Gb SFP+ uplinks.
The following figure shows the Lenovo Flex System EN4091 10Gb Ethernet Pass-thru.
Figure 1. Lenovo Flex System EN4091 10Gb Ethernet Pass-thru
Did you know?
The Lenovo Flex System EN4091 10Gb Ethernet Pass-thru module provides 14 internal and 14 external 10 Gb Ethernet ports, and it supports 1 Gb and 10 Gb Ethernet signaling for Converged Enhanced Ethernet (CEE), Fibre Channel over Ethernet (FCoE), and other Ethernet-based transport protocols.
Part number information
The Lenovo Flex System EN4091 10Gb Ethernet Pass-thru has 14 internal and 14 external ports that can operate at 1 Gb or 10 Gb Ethernet speeds. The following table shows the part numbers for ordering the Pass-thru module.
Table 1. Part numbers and feature codes for ordering
|Description||Part number||Feature code|
|Lenovo Flex System EN4091 10Gb Ethernet Pass-thru||88Y6043||A1QV|
The part number for the Lenovo Flex System EN4091 10Gb Ethernet Pass-thru, 88Y6043, includes the following items:
- One Lenovo Flex System EN4091 10Gb Ethernet Pass-thru module
- Important Notices flyer and Warranty Flyer
- Documentation CD-ROM
Note: SFP and SFP+ transceivers or cables are not included with the module.
Supported transceivers and cables
With the flexibility of the Flex System EN4091 10Gb Ethernet Pass-thru Module, clients can take advantage of the technologies that they require for multiple environments:
- For 1 GbE external links, clients can use RJ-45 SFP transceivers with UTP cables up to 100 m. Clients that need longer distances can use a 1000BASE-SX transceiver, which can drive distances up to 220 meters by using 62.5 µ multi-mode fiber and up to 550 meters with 50 µ multi-mode fiber, or the 1000BASE-LX transceivers that support distances up to 10 kilometers using single-mode fiber (1310 nm).
- For 10 GbE external links, clients can use SFP+ direct attach copper (DAC) cables for in-rack cabling and distances up to 5 m. These DAC cables have SFP+ connectors on each end, and they do not need separate transceivers. For longer distances the 10GBASE-SR transceiver can support distances up to 300 meters over OM3 multimode fiber or up to 400 meters over OM4 multimode fiber. The 10GBASE-LR transceivers can support distances up to 10 kilometers on single mode fiber.
The following table lists the supported cables and transceivers.
Table 2. Supported transceivers and DAC cables
|Description||Part number||Feature code||Maximum quantity supported|
|SFP transceivers - 1 GbE|
|Lenovo 1000BASE-T SFP Transceiver (does not support 10/100 Mbps)||00FE333||A5DL||14|
|Lenovo 1000BASE-SX SFP Transceiver||81Y1622||3269||14|
|Lenovo 1000BASE-LX SFP Transceiver||90Y9424||A1PN||14|
|SFP+ transceivers - 10 GbE|
|Lenovo 10GBASE-SR SFP+ Transceiver||46C3447||5053||14|
|Lenovo 10GBASE-LR SFP+ Transceiver||90Y9412||A1PM||14|
|Optical cables for 1 GbE SFP SX and 10 GbE SFP+ SR transceivers|
|Lenovo 1m LC-LC OM3 MMF Cable||00MN502||ASR6||14|
|Lenovo 3m LC-LC OM3 MMF Cable||00MN505||ASR7||14|
|Lenovo 5m LC-LC OM3 MMF Cable||00MN508||ASR8||14|
|Lenovo 10m LC-LC OM3 MMF Cable||00MN511||ASR9||14|
|Lenovo 15m LC-LC OM3 MMF Cable||00MN514||ASRA||14|
|Lenovo 25m LC-LC OM3 MMF Cable||00MN517||ASRB||14|
|Lenovo 30m LC-LC OM3 MMF Cable||00MN520||ASRC||14|
|SFP+ passive direct-attach cables - 10 GbE|
|Lenovo 1m Passive SFP+ DAC Cable||90Y9427||A1PH||14|
|Lenovo 1.5m Passive SFP+ DAC Cable||00AY764||A51N||14|
|Lenovo 2m Passive SFP+ DAC Cable||00AY765||A51P||14|
|Lenovo 3m Passive SFP+ DAC Cable||90Y9430||A1PJ||14|
|Lenovo 5m Passive SFP+ DAC Cable||90Y9433||A1PK||14|
|SFP+ active direct-attach cables - 10 GbE|
|Lenovo 1m Active SFP+ DAC Cable||95Y0323||A25A||14|
|Lenovo 3m Active SFP+ DAC Cable||95Y0326||A25B||14|
|Lenovo 5m Active SFP+ DAC Cable||95Y0329||A25C||14|
|Lenovo 1m Active DAC SFP+ Cable (replaces 95Y0323)||00VX111||AT2R||14|
|Lenovo 3m Active DAC SFP+ Cable (replaces 95Y0326)||00VX114||AT2S||14|
|Lenovo 5m Active DAC SFP+ Cable (replaces 95Y0329)||00VX117||AT2T||14|
The Flex System EN4091 10Gb Ethernet Pass-thru Module is particularly suited for the following clients:
- Clients who require direct connectivity of the compute nodes in the chassis to an external TOR data center switch
- Clients who are implementing a converged environment
- Clients who want to reduce total cost of ownership (TCO) and improve performance, while maintaining high levels of availability and security
- Clients who want to avoid oversubscription, which can result in congestion and loss of performance
Features and specifications
The Flex System EN4091 10Gb Ethernet Pass-thru Module has the following features and specifications:
- Internal ports: Fourteen internal full-duplex Ethernet ports that can operate at 1 Gb or 10 Gb speeds.
- External ports: Fourteen ports for 1 Gb or 10 Gb Ethernet SFP+ transceivers (support for 1000BASE-SX, 1000BASE-LX, 1000BASE-T, 10GBASE-SR, or 10GBASE-LR) or SFP+ copper direct-attach copper (DAC) cables. SFP+ modules and DAC cables are not included and must be purchased separately.
- An unmanaged device that has no internal Ethernet management port, but is able to provide its vital product data (VPD) to the secure management network in the Chassis Management Module.
The module supports the following IEEE standards:
- IEEE 802.3ab 1000BASE-T copper twisted pair Gigabit Ethernet
- IEEE 802.3z 1000BASE-SX short range fiber optics Gigabit Ethernet
- IEEE 802.3z 1000BASE-LX long range fiber optics Gigabit Ethernet
- IEEE 802.3ae 10GBASE-SR short range fiber optics 10 Gb Ethernet
- IEEE 802.3ae 10GBASE-LR long range fiber optics 10 Gb Ethernet
- 10GSFP+Cu SFP+ Direct Attach copper
Supported chassis and adapter cards
The pass-thru modules are installed in I/O bays in the rear of the Flex System chassis, as shown in the following figure. I/O modules are normally installed in pairs because ports on the I/O adapter cards installed in the compute nodes are routed to two I/O bays for redundancy and performance.
Figure 2. Location of the I/O module bays in the Flex System chassis
The EN4091 10Gb Ethernet Pass-thru Module can be installed in bays 1, 2, 3, and 4 of the chassis. Up to four EN4091 modules are supported in a chassis. A supported Ethernet adapter must be installed in the corresponding slot of the compute node.
In compute nodes that have an integrated dual-port 10 GbE network interface controller (NIC), NIC ports are routed to bays 1 and 2 with a specialized periscope connector, and the adapter card is not required. However, when needed, the periscope connector can be replaced with the adapter card. In that case, an integrated NIC is disabled.
The following table shows compatibility information for the EN4091 and Flex System chassis.
Table 3. Flex System chassis compatibility
|Description||Part number||Enterprise Chassis with CMM||Enterprise Chassis with CMM2||Carrier-grade Chassis with CMM2|
|Flex System EN4091 10Gb Ethernet Pass-thru||88Y6043||Yes||Yes||No|
The connections between the adapters installed in the compute nodes to the EN4091 modules installed in the chassis are shown in the following figure. The figure shows both half-wide servers, such as the x240 with two adapters, and full-wide servers, such as the x440 with four adapters.
Figure 3. Logical layout of the interconnects between I/O adapters and EN4091 modules
The following table shows the connections between the adapters installed in the compute nodes to the I/O module bays in the chassis.
4-port and 8-port adapters: With 4-port 1 GbE or 10 GbE or 8-port 10 GbE adapters, only up to two adapter ports can be used with the EN4091 pass-thru modules (one port per pass-thru module).
Table 4. Adapter to I/O bay correspondence
|I/O adapter slot|
in the server
|Port on the adapter||Corresponding I/O module bay in the chassis|
|Bay 1||Bay 2||Bay 3||Bay 4|
|Slot 1||Port 1||Yes|
|Slot 2||Port 1||Yes|
(full-wide compute nodes only)
(full-wide compute nodes only)
The following table lists the I/O adapters supported by the EN4091 10Gb Ethernet Pass-thru Modules.
Table 5. Network adapters
|Description||Part number||Feature code|
|10 Gb Ethernet|
|Embedded 10Gb Virtual Fabric Adapter in the x240||None||None|
|Embedded 10Gb Virtual Fabric Adapter in the x440||None||None|
|Flex System CN4022 2-port 10Gb Converged Adapter||88Y5920||A4K3|
|Flex System CN4052 2-port 10Gb Virtual Fabric Adapter||00JY800||A5RP|
|Flex System CN4054 10Gb Virtual Fabric Adapter (4-port)||90Y3554||A1R1|
|Flex System CN4054R 10Gb Virtual Fabric Adapter (4-port)||00Y3306||A4K2|
|Flex System CN4058S 8-port 10Gb Virtual Fabric Adapter||94Y5160||A4R6|
|Flex System EN4132 2-port 10Gb Ethernet Adapter||90Y3466||A1QY|
|1 Gb Ethernet|
|EN2024 4-port 1Gb Ethernet Adapter||49Y7900||A10Y|
|Embedded 1Gb Ethernet in the x220||None||None|
The adapters are installed in slots in each compute node. The following figure shows the locations of the slots in the x240 Compute Node. The positions of the adapters in the other supported servers are similar.
Figure 4. Location of the I/O adapter slots in the Flex System x240 Compute Node
Connectors and LEDs
The following figure shows the front panel of the Flex System EN4091 10Gb Ethernet Pass-thru Module.
Figure 5. Front panel of the Flex System EN4091 10Gb Ethernet Pass-thru
The front panel has the following components:
- LEDs that show the status of the module and the network:
- The OK LED indicates that the module has passed the power-on self-test (POST) with no critical faults and is operational.
- The blue Identify LED is used to identify the module physically by using the management software to illuminate it.
- The error LED (pass-thru module error) indicates that the module has failed the POST or detected an operational fault.
- Fourteen external SFP/SFP+ ports for 1 Gb or 10 Gb connections to external Ethernet devices.
- An Ethernet link OK LED and an Ethernet Tx/Rx LED for each external port on the module.
Network cabling requirements
The network cables that can be used with the Flex System EN4091 10Gb Ethernet Pass-thru Module are shown in the following table.
Table 6. G8052 network cabling requirements
|10 Gb Ethernet|
|10GBASE-SR SFP+ Transceiver (46C3447)||10GBASE-SR||Up to 30 m with fiber optic cables supplied by Lenovo (see Table 2); 850 nm OM3 multimode fiber cable up to 300 m or up to 400 m with OM4 multimode fiber||LC|
|10GBASE-LR SFP+ Transceiver (90Y9412)||10GBASE-LR||1310 nm single-mode fiber cable up to 10 km||LC|
|Direct attach cable||10GSFP+Cu||SFP+ DAC cables up to 5 m (see Table 2)||SFP+|
|1 Gb Ethernet|
|1000BASE-T SFP Transceiver (00FE333)||1000BASE-T||UTP Category 5, 5E, and 6 up to 100 meters||RJ-45|
|1000BASE-SX SFP Transceiver (81Y1622)||1000BASE-SX||Up to 30 m with fiber optic cables supplied by Lenovo (see Table 2); 850 nm multimode fiber cable up to 550 m (50 µ) or up to 220 m (62.5 µ)||LC|
|1000BASE-LX SFP Transceiver (90Y9424)||1000BASE-LX||1310 nm single-mode fiber cable up to 10 km||LC|
The EN4091 carries a 1-year, customer-replaceable unit (CRU) limited warranty. When installed in a chassis, these I/O modules assume your system’s base warranty and any Lenovo warranty service upgrade.
These are the approximate dimensions and weight of the Flex System EN4091 10Gb Ethernet Pass-thru:
- Height: 30 mm (1.2 in.)
- Width: 401 mm (15.8 in.)
- Depth: 317 mm (12.5 in.)
- Weight: 3.7 kg (8.1 lb)
Shipping dimensions and weight (approximate):
- Height: 114 mm (4.5 in.)
- Width: 508 mm (20.0 in.)
- Depth: 432 mm (17.0 in.)
- Weight: 4.1 kg (9.1 lb)
The Flex System EN4091 10Gb Ethernet Pass-thru conforms to the following regulations:
- United States FCC 47 CFR Part 15, Subpart B, ANSI C63.4 (2003), Class A
- IEC/EN 60950-1, Second Edition
- Canada ICES-003, issue 4, Class A
- Japan VCCI, Class A
- Australia/New Zealand AS/NZS CISPR 22:2006, Class A
- Taiwan BSMI CNS13438, Class A
- CE Mark (EN55022 Class A, EN55024, EN61000-3-2, EN61000-3-3)
- CISPR 22, Class A
- China GB 9254-1998
- Turkey Communique 2004/9; Communique 2004/22
- Saudi Arabia EMC.CVG, 28 October 2002
The following usage scenarios are described:
- EN4091 in the traditional 10 Gb Ethernet network
- EN4091 in the converged NAS or iSCSI network
- EN4091 in the converged FCoE network
EN4091 in the traditional 10 Gb Ethernet network
In the traditional 10 GbE network, the EN4091 pass-thru modules are connected to the TOR switches (such as the Lenovo RackSwitch G8272) through the 10 GbE SFP+ ports, as shown in the following figure.
Figure 6. EN4091 in the 10 GbE network
EN4091 in the converged NAS or iSCSI network
The EN4091 pass-thru module can be connected to a TOR switch (such as the Lenovo RackSwitch G8272) that can transport iSCSI and NFS/CIFS data blocks with support for Converged Enhanced Ethernet (CEE). The example scenario with NAS and iSCSI storage protocols is shown in the following figure.
Figure 7. EN4091 in the converged NAS or iSCSI network
EN4091 in the converged FCoE network
With FCoE, the EN4091 pass-thru can be connected to a converged TOR switch that supports Fibre Channel Forwarder (FCF) capability (such as the Lenovo RackSwitch G8264CS). The FCF provides capability to connect FCoE storage targets via native FCoE interfaces (end-to-end FCoE) or through FC/FCoE gateways that break out the FC connections and connect to the SAN switches and then in to the storage devices.
The example scenario with end-to-end FCoE is shown in the following figure.
Figure 8. EN4091 in the converged FCoE network: End-to-end FCoE
The example scenario with the FC/FCoE gateway is shown in the following figure.
Figure 9. EN4091 in the converged FCoE network: FC/FCoE gateway
Note: For a full listing of supported FCoE and iSCSI configurations, see the System Storage Interoperation Center (SSIC) website at:
Related publications and links
For more information, see the following Flex System EN4091 10Gb Ethernet Pass-thru Module product publications, available from the Flex System Information Center:
- Installation and User's Guide
Here are other useful references:
- US Announcement Letter 112-053
- Flex System Information Center
- Flex System Interoperability Guide
- Flex System Products and Technology, SG24-8255
- Product Guides for Flex System
- System x and Cluster Solutions configurator (x-config)
- System x Configuration and Options Guide:
- ServerProven for Flex System
This material has not been submitted to any formal IBM test and is published AS IS. It has not been the subject of rigorous review. IBM assumes no responsibility for its accuracy or completeness. The use of this information or the implementation of any of these techniques is a client responsibility and depends upon the client's ability to evaluate and integrate them into the client's operational environment.