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Certain IP protocols are not allowed within a VPC network. For more information, see always blocked traffic. Other protocols are restricted , to special uses (e.g., GRE), see VPC network overview.
Communication between a VM instance and its corresponding metadata server (
169.254.169.254). Is always allowed.Every network has two implied firewall rules that permit outgoing connections and block incoming connections. Firewall rules that you create can override these implied rules.
The default network is pre-populated with firewall rules that can be deleted or modified.
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