F5 Networks F5CAB5 Exam - Topic 4 Question 1 Discussion

Actual exam question for F5 Networks's F5CAB5 exam

Question #: 1
Topic #: 4

An organization is reporting slow performance accessing their Intranet website, hosted in a public cloud. All employees use a single Proxy Server with the public IP of 104.219.110.168 to connect to the Internet. What should the BIG-IP Administrator of the Intranet website do to fix this issue?

AChange Source Address to 104.219.110.168/32

BChange Load Balancing Method to Least Connection

CChange Fallback Persistence Profile to source_addr

DChange Default Persistence Profile to cookie

Show Suggested Answer

Suggested Answer: D

This scenario describes a classic network performance issue known as the 'Mega-Proxy' problem. When an organization routes all employee traffic through a single proxy server, the BIG-IP sees thousands of unique users as having the exact same source IP address. If the administrator has configured 'Source Address Affinity' persistence, the BIG-IP will correctly follow the rule but incorrectly route all users to the same single backend pool member. This creates a severe load imbalance where one server is overwhelmed while others remain idle, leading to poor application response times. To resolve this, the administrator must change the persistence profile to 'HTTP Cookie'. Cookie-based persistence allows the BIG-IP to place a unique identifier in each user's browser, allowing the system to distinguish between individual sessions even if they share the same source IP. This fix ensures that traffic is distributed evenly across the pool members, restoring4 the expect5ed load balancing functionality and resolving the slow performance reported by users behind the corporate proxy.

by Nan at Jan 25, 2026, 05:21 PM

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Mabel

15 hours ago

I think changing the Load Balancing Method to Least Connection makes sense.

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Jovita

6 days ago

Haha, this is a classic IT problem. Just throw some duct tape on it and call it a day!

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Andra

11 days ago

I don't know, but B) seems like the most logical choice to me.

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Earlean

16 days ago

D) sounds good to me. Cookies are the way of the future, man.

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Emilio

21 days ago

C) is the way to go. Changing the Fallback Persistence Profile to source_addr will help maintain client sessions.

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Lorrie

26 days ago

A) is the correct answer. Changing the Source Address to 104.219.110.168/32 will ensure the BIG-IP can properly identify the Proxy Server's IP address.

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Keena

1 month ago

I'm uncertain about the fallback persistence profile. Is "source_addr" really the best option for this scenario?

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Marylyn

1 month ago

I vaguely recall that persistence profiles can impact user sessions. Maybe switching to cookie persistence could help?

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Barney

2 months ago

This question feels similar to one we practiced on load balancing methods. I think "Least Connection" could help with performance issues.

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Cordell

2 months ago

I remember something about source address settings, but I'm not sure if changing it to 104.219.110.168/32 is the right move.

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Fernanda

2 months ago

I'm not totally confident, but I think option B, changing the Load Balancing Method to Least Connection, might also be a good approach. That could help distribute the load more evenly across the backend servers.

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Georgiana

3 months ago

I'm leaning towards option C, changing the Fallback Persistence Profile to source_addr. That would ensure each client is consistently routed to the same backend server, which could help with the performance issue.

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Shoshana

3 months ago

Okay, let's think this through. The question is asking what the BIG-IP Administrator should do, so I'm guessing the solution has to do with the load balancing or persistence settings on the BIG-IP.

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Tiara

3 months ago

Hmm, I'm not sure. The question mentions the Intranet website is hosted in a public cloud, so the proxy server might not be the issue. I'd need to look into that more.

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Clay

3 months ago

I think the key here is to identify the root cause of the slow performance. Since the employees are all using a single proxy server, that could be the bottleneck.

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