The X2-10GB-LR tranceiver is designed for Singlemode fiber (SMF) operation, not the Multimode fiber (MMF) you have installed.
Without changing out the fiber, you might try installing a pair of Mode Conditioning Patchcords. For the transmitting end of the links, these patch cords transition the transceiver's output from SMF to MMF, and offset the fibers so the laser light is transmitted in the the correct area of the MMF's core. You order them based on the core size of your installed MMF (you didn't mention what type of MMF you had). They are available from suppliers.
This is not an "approved" application for the "LR" module and I am not sure it will work. But given your limited distance, this implimentation may work. It might be worth giving it a try versus pulling new fiber (or until you pull new fiber).
Both X2-10GB-LR & X2-10GB-LX4 gives you nearly the same optical budget but i think will be limited by dispersion as LX4 have has 4 wavelength working at 2.5Gb have EDC(electronic Dispersion Compernsation) whereas LR have 10G so dispersion will be more for LR.
3. Pull SMF cable as you have LR optics.
I dont think there is multimode extender at 10G there are at 1G but not at 10G.
Thank you.... We definitely appreciate feedback from real world networks!
In many cases, the network may operate outside of the published specifications. As viyuan700 has pointed out, the assumptions used by the specification bodies are generous so that the links will operate properly over most links. These "loose" link losses, which include fiber, connector and system margin, plus dispersion effects, result in links that may operate over longer links than outlined by the 802.3 specifications.
There can be two problems with operating links outside the bounds of the Cisco's published specifications; if you need to contact Cisco TAC, you may not receive the support you need because you are operating the system outside the bounds of the published parameters for the device. The other is if you swap out a transceiver, the new transceiver may have a lower transmit power than the previous unit; which may result in a link that doesn't operate properly.
Again, we appreciate the real world feedback. Keep it coming!
We are pleased to announce availability of Beta software for 16.6.3. 16.6.3 will be the second rebuild on the 16.6 release train targeted towards Catalyst 9500/9400/9300/3850/3650 switching platforms. We are looking for early feedback from custome...