# Firewall - Block Port 9300
**URL:** https://discuss.elastic.co/t/firewall-block-port-9300/143629
**Category:** Elasticsearch
**Created:** [August 9, 2018, 4:45am UTC](https://discuss.elastic.co/t/firewall-block-port-9300/143629 "2018-08-09T04:45:08Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@sanket.maru](https://discuss.elastic.co/u/sanket.maru)
#### Post date: [August 9, 2018, 4:45am UTC](https://discuss.elastic.co/t/firewall-block-port-9300/143629/1 "2018-08-09T04:45:08Z")
I have a multi node cluster with 3 masters, 4 data nodes, 2 ingest nodes.
My cluster is working and I am blocking port 9300 on one of the data or master nodes. To block port 9300 which is used communicating between the nodes I am using below command :
sudo ufw deny 9300.
I can see in firewall status that 9300 port has been denied , but still I can see that search, post requests are being served by that node. I have enabled trace logging and can see in logs that every 30 seconds master is pinging data nodes and getting response.
Is this expected behaviour ? How Elastic is serving request even if port has been blocked.
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### Author:  [@system](https://discuss.elastic.co/u/system)
#### Post date: [September 6, 2018, 4:45am UTC](https://discuss.elastic.co/t/firewall-block-port-9300/143629/2 "2018-09-06T04:45:13Z")
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