Topic 9 Question 56
If network traffic between one Google Compute Engine instance and another instance is being dropped, what is the most likely cause?
The instances are on a network with low bandwidth.
The TCP keep-alive setting is too short.
The instances are on a default network with no additional firewall rules.
A firewall rule was deleted.
解説
Google Compute Engine (GCE) only allows network traffic that is explicitly permitted by your project's firewall rules to reach your instance. By default, all projects automatically come with a default network that allows certain kinds of connections. If you delete one of the default network firewall rules, then the associated traffic will no longer be allowed. Dropped traffic can be caused by the TCP keep-alive setting being too long, not by being too short. All GCE instances have high-bandwidth connections. Reference: https://cloud.google.com/compute/docs/troubleshooting#networktraffic
コメント(5)
D is right, traffic is allowed by implied rule which can be deleted (https://cloud.google.com/vpc/docs/firewalls#default_firewall_rules)
👍 8mpguard2020/02/23D is right
👍 2Ziegler2020/06/06https://cloud.google.com/compute/docs/troubleshooting/general-tips#communicatewithinternet the keep-alive is discussed here.
👍 2bnlcnd2021/02/06
シャッフルモード