TCP connection reject received; TCP connection dropped?

johncrowe

Hi There,

I hope everybody is well,

I'm just looking for some help in relation to these packets as you can see in the image below:

I used Wireshark to analyze these packets but had no success. A few people are experiencing this issue in different firewalls like TZ300, and TZ400. They are using the latest firmware and the rules are fine too. Nothing is blocking port 443.

They can't make calls over the Internet and the Internet sometimes appear slow.

I'm just looking for some tips on how to sort out these outgoing issues.

Regards,

TKWITS

Read up on how TCP works.

https://en.wikipedia.org/wiki/Transmission_Control_Protocol

https://learn.microsoft.com/en-us/troubleshoot/windows-server/networking/three-way-handshake-via-tcpip

The webservers are replying with RST packets for a reason.

MustafaA

@johncrowe , some of these IP addresses are associated to AWS EC2 instances. Have you looked at this issue from that perspective? You need to understand why those destination IP addresses are sending RST packets to terminate the TCP session. With the current limited information, I don't think this is a firewall issue.