Mastering GLBP: Your Guide to Host Dependent Mode

In which GLBP mode does the host remain the same with each request?

• A. Weighted Distribution
• B. Host Dependent
• C. Round-Robin
• D. Interface Weighing

Answer: (B)

In the context of GLBP (Gateway Load Balancing Protocol), the mode in which the host remains the same for each request is known as Host Dependent mode. This operating mode utilizes the MAC address of the host to determine which virtual gateway will be used for all packets coming from that host. Once a host is assigned a virtual gateway based on its MAC address, it consistently receives the same gateway for all its requests. This consistency is crucial for maintaining session state and ensuring interoperability between sessions that may not work well with changing gateways. In contrast, the other modes introduce variable assignment of gateways. For instance, Weighted Distribution varies the gateway assignment based on predefined weights, which could change assignments for hosts over time. Round-Robin cycles through the available gateways for each request without regard to the specific host, meaning a single host could use different gateways for consecutive requests. Interface Weighing also assigns gateways based on weights, but it operates at the interface level, further adding to variability. Thus, Host Dependent mode offers stability for individual hosts, making it ideal for scenarios where consistent gateway access is necessary.

The world of networking can often feel overwhelming, especially when it comes to concepts that seem as complex as they are crucial to maintaining a seamless operation. One such concept is the Gateway Load Balancing Protocol—or just GLBP for the rest of us. If you’re gearing up for the Cisco Certified Network Professional test, you’re going to encounter questions about these protocols. So, let's break down the host-dependent mode, where it shines, and how it compares to its counterparts.

You know what? The name says it all. In Host Dependent mode, each request sent from a device consistently uses the same gateway determined by the MAC address of that device. Picture this: you’re hosting a party, and you only allow access through one main door. All your guests have to enter and exit through that gate—the gate they got assigned based on who they are. That’s essentially how Host Dependent operates—keeping the guest (or in this case, the host) constant.

Why is that important? Well, think about the significance of maintaining session state. If you’re tuned into video calls or online gaming when connections drop or change randomly, it’s chaotic. This kind of disruption can mess with interoperability between sessions. Hence, a stable connection is paramount, and that’s where Host Dependent truly shines.

Now, let’s pivot a bit and peek into the other modes of GLBP. The first one that comes to mind is Weighted Distribution. Unlike Host Dependent, where you’re on a fixed path, this mode introduces a variable assignment of gateways based on predefined weights. Think of it like a buffet where some dishes are more popular and get served up more frequently. This variability can be engaging, but it’s not always consistent for your requests.

Then there's a mode called Round-Robin. Imagine sharing a chocolate bar with friends, passing it around rather than keeping it for yourself. This mode cycles through available gateways, offering a different one for each request. It’s great for equal distribution but can create chaos—much like the unpredictable nature of who gets the next bite of chocolate!

What about Interface Weighing? This mode is similar in spirit to Weighted Distribution but adds a layer of complexity by assigning gateways based on weights at the interface level. This can be exciting in certain situations, but it also means less predictability.

So, as you study, remember why you’re focusing on that simple yet powerful Host Dependent mode. Stability equals reliability, especially when networks become critical lifelines for communication and business operations. The other modes all have their best uses, but for consistent connections per host, nothing stands against Host Dependent.

As you prepare for the Cisco Certified Network Professional exam, keeping your facts straight on such nuances will not only help you breeze through questions but also solidify your understanding of how networks function in real-world scenarios. The balance of technical acuity and practical application is what sets you apart as a networking professional. Embrace that, and you’ll be well on your way to certification success!