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+### Understand the alert
+
+TCP reset is an abrupt closure of the session. It causes the resources allocated to the connection to be immediately released and all other information about the connection is erased.
+
+The Netdata Agent monitors the average number of sent TCP RESETS over the last 10 seconds. This can indicate a port scan or that a service running on the system has crashed. Additionally, it's a result of a high number of sent TCP RESETS. Furthermore, it can also indicate a SYN reset attack.
+
+### More about TCP Resets
+
+TCP uses a three-way handshake to establish a reliable connection. The connection is full duplex, and both sides synchronize (SYN) and acknowledge (ACK) each other. The exchange of these four flags
+is performed in three steps: SYN, SYN-ACK, and ACK. 
+
+When an unexpected TCP packet arrives at a host, that host usually responds by sending a reset packet back on the same connection. A reset packet is one with no payload and with the RST bit set in the TCP header flags. There are a few circumstances in which a TCP packet might not be expected. The most common cases are:
+
+1. A TCP packet received on a port that is not open.
+2. An aborting connection
+3. Half opened connections
+4. Time wait assassination
+5. Listening endpoint Queue is Full
+6. A TCP Buffer Overflow
+
+Basically, A TCP Reset usually occurs when a system receives data which doesn't agree with its view of the connection.
+
+When your system cannot establish a connection it will retry by default `net.ipv4.tcp_syn_retries` times.
+
+### Troubleshoot the alert
+
+- Use tcpdump to capture the traffic and use Wireshark to inspect the network packets. You must stop the capture after a certain observation period (60s up to 5 minutes). This command will create a dump file which can be interpreted by Wireshark that contains all the TCP packets with RST flag set.
+  ```
+  tcpdump -i any 'tcp[tcpflags] & (tcp-rst) == (tcp-rst)' -s 65535 -w output.pcap
+  ```
+
+- Identify which application sends TCP resets
+
+1. Check the instances of `RST` events of the TCP protocol. Wireshark also displays the ports on which the two systems tried to establish the TCP connection, (XXXXXX -> XXXXXX).
+2. To check which application is using this port, run the following code:
+    ```
+    lsof -i:XXXXXX -P -n
+    ```
+### Useful resources
+
+1. [TCP reset explanation](https://www.pico.net/kb/what-is-a-tcp-reset-rst/)
+2. [TCP 3-way handshake on wikipedia](https://en.wikipedia.org/wiki/Handshaking)
+3. [Read more about Wireshark here](https://www.wireshark.org/)
+\ No newline at end of file