mediumMultiple Choice
350-401 Practice Question: Given the following SD-WAN configuration on a…
Given the following SD-WAN configuration on a Cisco IOS-XE router:
router ospf 1
redistribute bgp 65000 subnets
network 192.168.1.0 0.0.0.255 area 0
!
interface GigabitEthernet0/0/0 ip address 192.168.1.1 255.255.255.0 ip ospf network point-to-point
!
Which statement is true?
⚠ Common exam trap
Cisco often tests the default OSPF timer values for different network types, specifically tricking candidates into thinking point-to-point uses 30-second hello or 120-second dead intervals, which are actually defaults for NBMA networks.
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 OSPF network type is point-to-point, so the hello interval defaults to 10 seconds on this interface.
On a Cisco IOS-XE router, when the OSPF network type is set to point-to-point, the default hello interval is 10 seconds (not 30 seconds as on broadcast networks). The dead interval defaults to 40 seconds (four times the hello interval), not 120 seconds. This configuration is valid and does not require a manually configured router-id, as OSPF can dynamically select one. The redistribution of BGP into OSPF only injects routes that are in the BGP table; it does not automatically include all SD-WAN overlay routes unless they are present in BGP.
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 OSPF network type is point-to-point, so the hello interval defaults to 10 seconds on this interface.
Why this is correct
On a point-to-point OSPF network type, Cisco's default hello interval is 10 seconds, identical to the default on broadcast networks. This is because both network types use the same timer defaults on Cisco IOS, and the dead interval is then calculated as 4 × 10 = 40 seconds. Since the option specifically addresses the hello interval, it is correct.
- ✗
The OSPF network type is point-to-point, so the dead interval defaults to 120 seconds.
Why it's wrong here
The default OSPF dead interval on a point-to-point network is 40 seconds, not 120 seconds. This value is four times the default hello interval of 10 seconds, so 120 seconds would only be correct if the hello interval were 30 seconds, which is not the case on point-to-point networks. Therefore, the claim of a 120-second default dead interval is incorrect.
- ✗
The redistribution of BGP into OSPF will cause OSPF to advertise all BGP routes, including those learned via SD-WAN overlay.
Why it's wrong here
Redistribution of BGP into OSPF will redistribute BGP routes, but OSPF will only advertise routes that match the network statement or are redistributed. However, the statement is too broad and may not be accurate for all BGP routes; also, SD-WAN overlay routes are typically in a separate VRF.
- ✗
The configuration is incomplete because OSPF requires a router-id to be manually configured.
Why it's wrong here
OSPF does not require a manually configured router-id; if none is configured, the router dynamically selects one using the highest loopback IP address, or if no loopback exists, the highest active interface IP address. Manual configuration is a best practice for stability because it prevents the router-id from changing when interfaces go down, but its absence does not make the configuration incomplete. Thus, this option incorrectly identifies a missing required step.
Visual reference
Quick reference
Routing Protocol Comparison
| Protocol | Metric | Max Hops | Algorithm | Type |
|---|---|---|---|---|
| RIP v2 | Hop count | 15 | Bellman-Ford | Distance vector |
| OSPF | Cost (bandwidth) | Unlimited | Dijkstra (SPF) | Link state |
| EIGRP | Composite metric | Unlimited | DUAL | Hybrid |
| IS-IS | Cost | Unlimited | Dijkstra | Link state |
| BGP | Policy / attributes | Unlimited | Path vector | Path vector |
RIP's 15-hop limit makes it unsuitable for large networks. OSPF and EIGRP dominate modern enterprise deployments.
Go deeper
Related to this question
About these practice questions
One of 1,923 original 350-401 practice questions on Courseiva, each with a full explanation and wrong-answer analysis — not exam dumps or protected exam content. Learn why practice questions differ from exam dumps →
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This 350-401 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 350-401 exam.