DNS resolution across VPCs connected via S2S VPN

##### ISSUE TYPE

* Feature Idea

##### COMPONENT NAME

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VR
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##### CLOUDSTACK VERSION

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4.20
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##### CONFIGURATION

##### OS / ENVIRONMENT

##### SUMMARY

Current VR only resolve its own Guest Network DNS zone record and external records. When two or more peered VPC network, user has to manage the host resolution either by host file or create another forwarder point to VR in upstream DNS. I would say it would be more useful if we populate all DNS record across each peered zone VR with proper domain suffix. So the user do not need to discover new IP changes from peered zone.

##### STEPS TO REPRODUCE

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##### EXPECTED RESULTS

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##### ACTUAL RESULTS

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Start by examining the CloudStack VR component and how peered VPC DNS zones are represented in version 4.20. Clarify the expected domain suffixes, record propagation behavior, and user-facing usage before identifying the relevant implementation and tests; done means DNS resolution works across peered VPCs without host-file or upstream-forwarder management.

Written by the indexing model from the issue text.