Nov 10, 2018

Google Compute Engine firewall example

Outbound SMTP connections are blocked by the Google Compute Engin, but there is no problem for incoming. To allow default SMTP port 25

$ gcloud compute firewall-rules create rulesmtp --allow tcp:25
Created [https://www.googleapis.com/compute/v1/projects/i88.ca:cloud-sqll/global/firewalls/rulesmtp].
NAME     NETWORK SRC_RANGES RULES  SRC_TAGS TARGET_TAGS
rulesmtp default 0.0.0.0/0  tcp:25

$ telnet 188.188.188.188 25
Trying 188.188.188.188...
Connected to 188.188.188.188.
Escape character is '^]'.
220 example.c.cloud-sqll.i88.ca.internal ESMTP Postfix (Ubuntu)

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