hardMultiple Choice
300-410 Practice Question: The default behavior of BGP synchronization in…
What is the default behavior of BGP synchronization in Cisco IOS-XE?
⚠ Common exam trap
300-410 often tests the outdated belief that BGP synchronization is enabled by default, when in fact Cisco disabled it by default in modern IOS/IOS-XE releases.
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
✓
Disabled by default
In Cisco IOS and IOS-XE, BGP synchronization is disabled by default. Historically it was enabled to prevent advertising iBGP-learned routes until they were confirmed via IGP, but modern designs (especially with full iBGP meshes or route reflectors) made it obsolete, so Cisco disabled it by default. Administrators must explicitly enable it with the synchronization command under router bgp if needed.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Enabled by default
Why it's wrong here
BGP synchronisation is disabled by default in Cisco IOS-XE, so no route is held back awaiting an IGP match. It is tempting because older IOS releases and some service-provider designs enable it, where it would correctly prevent advertising iBGP routes before the IGP converges.
- ✓
Disabled by default
Why this is correct
BGP synchronization is disabled by default in Cisco IOS-XE, so routes learned via IBGP need not await matching IGP entries before advertisement to EBGP peers. This satisfies the stem's default-behaviour constraint: no explicit `no synchronization` command is required, unlike legacy IOS where it was enabled.
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Enabled only for iBGP
Why it's wrong here
BGP synchronisation is disabled by default on Cisco IOS-XE regardless of peer type, so it is not enabled for iBGP alone. It is tempting because synchronisation historically applied to iBGP-learned routes before advertisement to eBGP, and it would be correct if the question asked about legacy IOS behaviour with sync explicitly configured.
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Disabled only for eBGP
Why it's wrong here
Synchronisation is disabled by default for both iBGP and eBGP; there is no default state where it applies only to eBGP. It is tempting because eBGP is the peer type synchronisation rules govern, and it would be correct if the question described a scenario where sync was manually enabled and then selectively applied.
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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 Cisco exam blueprint
This 300-410 practice question is part of Courseiva's free Cisco 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 300-410 exam.