Question 25

Question

Your on-premises data center has 2 routers connected to your Google Cloud environment through a
VPN on each router. All applications are working correctly; however, all of the traffic is passing across
a single VPN instead of being load-balanced across the 2 connections as desired.
During troubleshooting you find:
• Each on-premises router is configured with a unique ASN.
• Each on-premises router is configured with the same routes and priorities.
• Both on-premises routers are configured with a VPN connected to a single Cloud Router.
• BGP sessions are established between both on-premises routers and the Cloud Router.
• Only 1 of the on-premises router’s routes are being added to the routing table.
What is the most likely cause of this problem?

Accepted Answer

The ASNs being used on the on-premises routers are different.

Alex J. · Answer

D is right because ECMP in Google Cloud needs both on-prem routers to share the same ASN. If they're different, Cloud Router only adds one path since BGP sees routes as separate. Pretty sure that's it, but someone correct me if I'm off.

Jamie · Answer

A is wrong, D. When on-prem routers use different ASNs, ECMP can't kick in for the Cloud Router so only one route gets picked. Saw this covered in the official guide and Google docs. If you want to drill on stuff like this, hit labs or the practice test sets. Pretty sure D is what they want here but open to challenges.

Riley F. · Answer

Its D. ECMP (Equal Cost Multi-Path) only works when both on-prem routers use the same ASN, otherwise Cloud Router won't see the BGP routes as equal and won't load-balance. Saw a similar question before. Let me know if you think differently.

Google Professional Cloud Network Engineer Real Exam Questions [October 2026 Update] Quiz

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