Understanding 1000BASE-LX Connections: Unraveling the Distances

What is the maximum distance of a 1000BASE-LX connection using multimode fiber?

• A. 3 km
• B. 10 km
• C. 220 m
• D. 400 m

Answer: (A)

The maximum distance for a 1000BASE-LX connection using multimode fiber is indeed defined in terms of its specifications. However, it is important to point out that 1000BASE-LX is primarily intended for use with single-mode fiber, which allows for longer distances, typically up to 10 kilometers or more. When using multimode fiber, the effective range is limited. Although multimode fiber connections can extend up to 850 nm, the maximum distance typically achieved for 1000BASE-LX with multimode fiber is around 550 meters under ideal conditions. This differs significantly from the values provided in the choices. Therefore, the longest possible distance for a 1000BASE-LX connection on multimode fiber does not match the value indicated; in fact, the actual typical distance does not exceed a few hundred meters. Knowing this helps clarify the confusion around the specifications for multimode versus single-mode fiber connections. In summary, while the maximum distance for multimode fiber in the context of 1000BASE technology is significantly shorter than the options suggest, the most common and realistic distance with multimode fiber is around 400 meters and not 3 km as previously selected.

When it comes to 1000BASE-LX connections, understanding the distances involved can be like navigating a maze. You're studying for that Cisco Certified Network Associate (CCNA) exam, right? So, let's unravel some details together.

First off, a common question that pops up is, “What is the maximum distance of a 1000BASE-LX connection using multimode fiber?” And the options might lead you down some interesting paths: A. 3 km, B. 10 km, C. 220 m, or D. 400 m. What's your gut telling you? If you guessed A, you're not alone—but let's shed some light on why that's not quite the whole story.

The correct answer is actually around 400 meters for multimode fiber. You see, 1000BASE-LX is primarily designed with single-mode fiber in mind, where the distance can stretch up to an impressive 10 kilometers or more. When we talk about multimode fiber, we're stepping into a whole different ballpark.

Now, don't let that confuse you; multimode fiber can work well for shorter distances—under ideal conditions, you might hit 550 meters — but that’s still not the 3 km you might have initially thought. You know what? The numbers can be tricky!

So why the discrepancy? Well, multimode connections have their limits. Although they can operate at wavelengths up to 850 nm, the maximum distance you can realistically achieve with them is usually capped at around 400 meters for 1000BASE-LX technologies. Isn’t that wild? This illustrates the crucial difference between the two types of fiber and why understanding these specifications is critical, especially for aspiring network professionals gearing up for CCNA.

It’s a bit like comparing a sports car to a rally car; both are built for speed, but they excel in different environments. In essence, when managing a network, careful consideration of your infrastructure will make all the difference. By getting your head around the distinctions between single-mode and multimode fibers, you'll not only ace that exam but also make informed decisions in your career.

So, remember: the maximum distance for a 1000BASE-LX connection using multimode fiber doesn't match the 3 km that's on the tip of your tongue. It's a common pitfall, but understanding the limitations of multimode fiber is what helps clarify your knowledge. Keep striving, studying, and soon you'll be well-equipped to tackle any questions that come your way!