SYN flooding during boot-up

I am getting a flood of unACKed SYNs during boot-up/start of ElasticSearch servers that sends the servers into syncookie mode.

Server log: "Possible SYN flooding on port 9300. Sending cookies."

Is this normal?

Its probably a result of the initial connection done between the nodes in the cluster. How many nodes do you have? If they connect, then all is well, and you don't see the messages, then all is well.
On Thursday, March 3, 2011 at 7:48 PM, Sorostaran wrote:

I am getting a flood of unACKed SYNs during boot-up/start of Elasticsearch
servers that sends the servers into syncookie mode.

Server log: "Possible SYN flooding on port 9300. Sending cookies."

Is this normal?

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