- A
The route-map has a match clause that matches both subnets, causing traffic to be load-balanced across both next-hops. Use specific ACLs or separate route-map entries.
If the ACL in the route-map matches both subnets (e.g., using a wildcard mask that is too broad), traffic from 10.1.1.0/24 can match multiple clauses, leading to load-balancing. Using specific ACLs or separate route-map entries with sequence numbers ensures each subnet is matched by only one clause.
- B
The 'set ip next-hop' command is missing the 'load-balance' keyword, causing PBR to use both next-hops by default.
Why wrong: PBR does not load-balance by default. It uses the first matching clause. The 'load-balance' keyword is not a standard PBR command; PBR uses 'set ip next-hop' with multiple next-hops for redundancy, not load-balancing.
- C
The routing table on R1 has equal-cost routes to both ISPs, causing PBR to be overridden by the routing table.
Why wrong: PBR overrides the routing table for matched traffic. The debug output shows PBR is forwarding traffic, so the routing table is not the issue.
- D
The interface where PBR is applied is in a VRF, causing the route-map to be applied incorrectly.
Why wrong: If the interface were in a VRF, the PBR configuration would need to be VRF-aware, but the symptom is about load-balancing, not VRF issues.
Quick Answer
The root cause is that the route-map contains a match clause with an overlapping ACL that matches both subnets, causing traffic from 10.1.1.0/24 to hit multiple clauses and be load-balanced across both next-hops. In PBR, when a route-map has multiple match statements without mutually exclusive ACLs or explicit sequence numbers, a single packet can satisfy more than one match, leading to unintended per-packet load balancing. This tests your understanding of how Cisco IOS processes route-map sequences sequentially—if the first match does not explicitly deny the other subnet, traffic will fall through to subsequent clauses. On the CCNP ENARSI 300-410 exam, this is a classic trap: candidates often assume separate match clauses automatically isolate traffic, but without specific ACLs or deny statements, overlapping matches cause the PBR load balancing overlapping match issue. The fix is to use distinct ACLs for each subnet or add sequence numbers with explicit deny entries. Memory tip: “Match must be mutually exclusive, or your PBR gets per-packet exclusive.”
300-410 Policy-Based Routing (PBR) Practice Question
This 300-410 practice question tests your understanding of policy-based routing (pbr). Examine the command output carefully: the correct answer depends on what the output actually shows, not on general recall alone. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
A network uses PBR to load-balance traffic from two subnets (10.1.1.0/24 and 10.2.2.0/24) across two ISPs (next-hops 100.64.1.1 and 100.64.2.2). After a routing change, traffic from 10.1.1.0/24 is being sent to both ISPs intermittently. Router R1 shows: 'show route-map' shows the route-map with two match clauses, 'debug ip policy' shows traffic from 10.1.1.0/24 being sent to both next-hops. What is the root cause?
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 route-map has a match clause that matches both subnets, causing traffic to be load-balanced across both next-hops. Use specific ACLs or separate route-map entries.
PBR route-maps can have multiple match clauses, but if the route-map does not have a 'sequence' number or if the match clauses are not mutually exclusive, traffic can match multiple clauses. In this case, the route-map likely has a match clause that matches both subnets (e.g., using a less specific ACL), causing traffic from 10.1.1.0/24 to match both clauses and be load-balanced. The solution is to ensure the ACLs in the route-map are mutually exclusive or use separate route-map entries with sequence numbers.
Key principle: Count usable hosts — not total addresses — and remember that the network and broadcast addresses are not available to hosts in standard IPv4 subnets.
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 route-map has a match clause that matches both subnets, causing traffic to be load-balanced across both next-hops. Use specific ACLs or separate route-map entries.
Why this is correct
If the ACL in the route-map matches both subnets (e.g., using a wildcard mask that is too broad), traffic from 10.1.1.0/24 can match multiple clauses, leading to load-balancing. Using specific ACLs or separate route-map entries with sequence numbers ensures each subnet is matched by only one clause.
Related concept
CIDR notation defines the prefix length.
- ✗
The 'set ip next-hop' command is missing the 'load-balance' keyword, causing PBR to use both next-hops by default.
Why it's wrong here
PBR does not load-balance by default. It uses the first matching clause. The 'load-balance' keyword is not a standard PBR command; PBR uses 'set ip next-hop' with multiple next-hops for redundancy, not load-balancing.
- ✗
The routing table on R1 has equal-cost routes to both ISPs, causing PBR to be overridden by the routing table.
Why it's wrong here
PBR overrides the routing table for matched traffic. The debug output shows PBR is forwarding traffic, so the routing table is not the issue.
- ✗
The interface where PBR is applied is in a VRF, causing the route-map to be applied incorrectly.
Why it's wrong here
If the interface were in a VRF, the PBR configuration would need to be VRF-aware, but the symptom is about load-balancing, not VRF issues.
Common exam traps
Common exam trap: usable hosts are not the same as total addresses
Subnetting questions often tempt you into counting all addresses. In normal IPv4 subnets, the network and broadcast addresses are not usable host addresses.
Trap categories for this question
Keyword trap
PBR does not load-balance by default. It uses the first matching clause. The 'load-balance' keyword is not a standard PBR command; PBR uses 'set ip next-hop' with multiple next-hops for redundancy, not load-balancing.
Command / output trap
PBR does not load-balance by default. It uses the first matching clause. The 'load-balance' keyword is not a standard PBR command; PBR uses 'set ip next-hop' with multiple next-hops for redundancy, not load-balancing.
Detailed technical explanation
How to think about this question
Subnetting questions test whether you can identify the network, broadcast address, usable range, mask and correct subnet. Slow down enough to calculate the block size correctly.
KKey Concepts to Remember
- CIDR notation defines the prefix length.
- Block size helps identify subnet boundaries.
- Network and broadcast addresses are not usable hosts in normal IPv4 subnets.
- The required host count determines the smallest suitable subnet.
TExam Day Tips
- Write the block size before choosing the subnet.
- Check whether the question asks for hosts, subnets or a specific address range.
- Do not confuse /24, /25, /26 and /27 host counts.
Key takeaway
Count usable hosts — not total addresses — and remember that the network and broadcast addresses are not available to hosts in standard IPv4 subnets.
Real-world example
How this comes up in practice
A security administrator must allow nursing staff to reach a patient records server while blocking access from the guest Wi-Fi VLAN. After applying an extended ACL, traffic is still blocked from nursing workstations. The ACL was applied outbound instead of inbound on the wrong interface. Questions like this test ACL direction and placement rules.
What to study next
Got this wrong? Here's your next step.
Review block sizes, usable host formulas (2^n − 2), and how to find network and broadcast addresses for /24 through /30. Then practise related 300-410 subnetting questions on CIDR, address ranges, and subnet selection.
- →
Policy-Based Routing (PBR) — study guide chapter
Learn the concepts, then practise the questions
- →
Policy-Based Routing (PBR) practice questions
Targeted practice on this topic area only
- →
All 300-410 questions
2,152 questions across all exam domains
- →
Cisco CCNP ENARSI 300-410 study guide
Full concept coverage aligned to exam objectives
- →
300-410 practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Related 300-410 practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Layer 3 Technologies practice questions
Practise 300-410 questions linked to Layer 3 Technologies.
EIGRP Troubleshooting practice questions
Practise 300-410 questions linked to EIGRP Troubleshooting.
OSPF Troubleshooting (v2/v3) practice questions
Practise 300-410 questions linked to OSPF Troubleshooting (v2/v3).
BGP Troubleshooting practice questions
Practise 300-410 questions linked to BGP Troubleshooting.
Route Redistribution practice questions
Practise 300-410 questions linked to Route Redistribution.
Policy-Based Routing (PBR) practice questions
Practise 300-410 questions linked to Policy-Based Routing (PBR).
VRF-Lite practice questions
Practise 300-410 questions linked to VRF-Lite.
Route Maps and Route Filtering practice questions
Practise 300-410 questions linked to Route Maps and Route Filtering.
Administrative Distance practice questions
Practise 300-410 questions linked to Administrative Distance.
Route Summarization practice questions
Practise 300-410 questions linked to Route Summarization.
Bidirectional Forwarding Detection (BFD) practice questions
Practise 300-410 questions linked to Bidirectional Forwarding Detection (BFD).
VPN Technologies practice questions
Practise 300-410 questions linked to VPN Technologies.
Practice this exam
Start a free 300-410 practice session
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
FAQ
Questions learners often ask
What does this 300-410 question test?
Policy-Based Routing (PBR) — This question tests Policy-Based Routing (PBR) — CIDR notation defines the prefix length..
What is the correct answer to this question?
The correct answer is: The route-map has a match clause that matches both subnets, causing traffic to be load-balanced across both next-hops. Use specific ACLs or separate route-map entries. — PBR route-maps can have multiple match clauses, but if the route-map does not have a 'sequence' number or if the match clauses are not mutually exclusive, traffic can match multiple clauses. In this case, the route-map likely has a match clause that matches both subnets (e.g., using a less specific ACL), causing traffic from 10.1.1.0/24 to match both clauses and be load-balanced. The solution is to ensure the ACLs in the route-map are mutually exclusive or use separate route-map entries with sequence numbers.
What should I do if I get this 300-410 question wrong?
Review block sizes, usable host formulas (2^n − 2), and how to find network and broadcast addresses for /24 through /30. Then practise related 300-410 subnetting questions on CIDR, address ranges, and subnet selection.
What is the key concept behind this question?
CIDR notation defines the prefix length.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
Last reviewed: Jun 18, 2026
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.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.