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New Member

X2-10GB-LX4 to SFP-10G-LRM= Compatibility


Can you help me in this ?

I have two 10Gig modules.

On 6500, i have X2-10GB-LX4  and on 3750-x i have SFP-10G-LRM= . Upon connecting the fiber cable, link is not getting up. i am searching for similar kind of problems faced by other ppl but only one reference i found out about their incompatibility, but i think it is not correct as cisco mention in the data sheet that they are compatible.

Also, i checked the mode conditioning patch cord requirement for this but it is required for OM1 and OM2..and i am using OM3 patch cord.

Trying to solve this for couple of days, but still struggling. do let me know if you has experienced the same or know any thing how it can work.

Everyone's tags (2)
Cisco Employee

X2-10GB-LX4 to SFP-10G-LRM= Compatibility

They are not compatible.

LX4 is under IEEE 802.3ae and LRM is under IEEE 802.3aq. Two different standard.

Under this document, Table-2, it describes the LX4 is using 4 LANE which means it use 4 lasers to achieve 10G throughput



New Member

X2-10GB-LX4 to SFP-10G-LRM= Compatibility

Thanks for your reply. Please check following taken from the data sheets.

Cisco 10GBASE X2 Modules (X2-10GB-LX4 )

• Has optical interoperability with respective 10GBASE Xenpak, 10GBASE XFP and 10GBASE SFP+ modules on the same link.


IEEE 802.3ae (-LR, -SR, -LX4, -ER)

Cisco 10GBASE SFP+ Modules (SFP-10G-LRM=)

  • Optical interoperability with 10GBASE XENPAK, 10GBASE X2, and 10GBASE XFP interfaces on the same link

Regulatory and Standards Compliance


IEEE 802.3ae (-SR, -LRM, LR, -ER)

So as per their respective DataSheet both X2-10GB-LX4 and SFP-10G-LRM= are interoperable and IEEE 802.3ae compliant.



Cisco Employee

X2-10GB-LX4 to SFP-10G-LRM= Compatibility

Once again, per the following link


• IEEE 802.3ae (-LR, -SR, -LX4, -ER)

• IEEE 802.3ak (-CX4)

• IEEE 802.3aq (-LRM)

Look at Type between LRM and LX4:

LRM - 1310nm MMF

LX4 - WWDM 1300 nm MMF

LX4 is using WDM - wave division multiplexing. And this is why the table said 4 lanes (4 lasers).

LRM and LX4 is not compatible.



New Member

Jerry is right.

Jerry is right.

LX4 & LRM are not compatible.

And to my knowledge, LX4 is only compatible with LX4.