F5-CTS-LTM BIG-IP Local Traffic Manager Practice Question
Which THREE conditions must be met for Connection Mirroring to function correctly between two BIG-IP devices in a high-availability pair?
⚠ Common exam trap
Candidates often assume enabling connection mirroring globally is enough, forgetting that it must also be explicitly configured on individual virtual servers and VLANs.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
The devices must be members of a Sync-Failover device group.
Connection Mirroring requires specific synchronization prerequisites. The devices must be in a device group, a mirror IP address must be defined for the VLANs, and the virtual server must have mirroring explicitly enabled. This ensures that the state information of TCP and persistence sessions is replicated, allowing for hitless failover where clients do not have to re-establish their connections upon a standby-to-active transition.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
The devices must be members of a Sync-Failover device group.
Why this is correct
Connection mirroring requires the devices to be part of a synchronization and failover device group. This ensures that the secondary device is aware of the primary's configuration and can actively participate in the state synchronization process required to maintain persistent connections during a failover event.
- ✓
The virtual server must have mirroring enabled in its configuration.
Why this is correct
Mirroring is an optional feature on virtual servers that must be explicitly enabled. By default, connection state is not mirrored to conserve resources. Enabling this setting informs the BIG-IP to replicate state table entries for that specific virtual server to the peer device in real time.
- ✓
A mirroring IP must be configured for the VLANs in use.
Why this is correct
A primary mirror address must be assigned to the VLAN used for synchronization traffic. This address identifies the interface through which the state data is transmitted between the HA pair, ensuring that the traffic is isolated and doesn't interfere with standard production traffic flows on other interfaces.
- ✗
The virtual server must use a 'Fast L4' profile.
Why it's wrong here
While Fast L4 profiles support mirroring, it is not a requirement. Standard TCP profiles and other protocol profiles also support connection mirroring. The critical factor is enabling the feature at the virtual server level, rather than being restricted to a specific type of L4 profile configuration.
- ✗
The pool members must be in the same subnet as the BIG-IP.
Why it's wrong here
The subnet location of the pool members is irrelevant to the function of connection mirroring. Mirroring is a process strictly between the BIG-IP HA pair devices to synchronize the state of the client-side connections, and it does not depend on the network topology of the backend server pool.
Visual reference
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JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official F5 exam blueprint
This F5-CTS-LTM practice question is part of Courseiva's free F5 certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the F5-CTS-LTM exam.