NIC Teaming Load Balancing
A company deploys a VDS with multiple uplinks and uses Route based on originating virtual port for load balancing. The network team reports that traffic from VMs on the same host is not balanced across uplinks. The administrator verifies that the physical switch ports are all in the same port-channel. What could be the cause?
Quick Answer
The uplinks being configured in active/standby mode is the cause because that setting overrides whatever load-balancing algorithm is selected; Route based on originating virtual port only comes into play when multiple uplinks are actually active and eligible to carry traffic simultaneously. If one uplink is standby, the vDS never sends any traffic down it under normal conditions no matter what the algorithm says, so all VM traffic funnels through the single active uplink and no distribution happens at all. This is easy to mistake for an algorithm problem, since Route based on originating virtual port is itself a fairly basic, statically assigned scheme, but the absence of load balancing described here has a more fundamental cause sitting one layer up in the uplink failover order settings. The physical switch's port-channel configuration is a bit of a red herring too, since that algorithm does not rely on the physical switch understanding any particular hashing behavior the way IP hash with LACP would. Ruling out too few VMs or explicit failover order settings makes sense as well, since those would only reduce or reshape distribution, not eliminate it outright. Whenever a scenario says load balancing is not happening at all rather than just being uneven, check the uplink's active/standby state before questioning the teaming algorithm itself.
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 uplinks are configured in active/standby mode
When uplinks are configured in active/standby mode, only one uplink is active at a time, so no load balancing occurs regardless of the algorithm. Option B is incorrect because Route based on originating virtual port is a vSphere algorithm and does not depend on physical switch support. Option C is incorrect because having fewer VMs than uplinks might reduce distribution but does not prevent load balancing entirely; traffic could still be balanced across active uplinks. Option D is incorrect because an explicit failover order can still allow multiple active uplinks if multiple paths are set to active; it is not the same as active/standby.
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 uplinks are configured in active/standby mode
Why this is correct
In active/standby mode, only one uplink is active, so no load balancing occurs.
- ✗
The load balancing algorithm is not supported by the physical switch
Why it's wrong here
Route based on originating virtual port is a vSphere-only algorithm and does not require physical switch support.
- ✗
The number of VMs is less than the number of uplinks
Why it's wrong here
Even with fewer VMs, traffic should be distributed across active uplinks based on the algorithm.
- ✗
The teaming policy uses an explicit failover order
Why it's wrong here
Explicit failover order can still have multiple uplinks in the active list; if so, load balancing should work.
Go deeper
Related to this question
About these practice questions
This VCP-DCV question is part of Courseiva's 498-question bank — original exam-style content with full explanations and wrong-answer analysis, never real exam questions or exam dumps. Learn why practice questions differ from exam dumps →
Same concept, more angles
1 more way this is tested on VCP-DCV
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. A vSphere administrator needs to provide redundancy for VM traffic on a vSphere Standard Switch by using multiple physical uplinks. Which teaming configuration should be used to ensure that if one uplink fails, traffic automatically fails over to another?
easy- A.Set load balancing to 'Route based on IP hash' and make both uplinks active.
- B.Enable 'Use explicit failover order' and configure 'Network failures' detection.
- C.Set load balancing to 'Explicit failover order' and set one uplink as active.
- ✓ D.Set load balancing to 'Route based on originating virtual port' and make one uplink active and one standby.
Why D: Option D is correct because setting load balancing to 'Route based on originating virtual port' with one active and one standby adapter explicitly configures a failover pair: if the active uplink fails, the standby automatically takes over, ensuring redundancy. Option A is incorrect because while an active/active configuration with 'Route based on IP hash' can provide failover, it is designed primarily for load balancing and requires proper EtherChannel setup on the physical switch; for simple redundancy, the active/standby configuration is the direct and recommended approach. Option B is incorrect because enabling 'Use explicit failover order' does not by itself designate a standby adapter; you must also configure the active/standby assignments. Option C is incorrect because having only one active uplink with no standby leaves no failover target if that uplink fails. Therefore, D is the correct answer.
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This VCP-DCV practice question is part of Courseiva's free VMware 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 VCP-DCV exam.