The Job Server is not responding (Designer can't run jobs)

Hello everyone,

The architecture is the following: Linux SAP DS server installation on virtual machine and client Designer in local Windows 7.

When trying to change the environment designer communication ports, it gives the error Job Server is not responding.

Here is a list of things which I checked:

• I can ping linux VM server from windows host (ping 192.168.56.101)
• I can ping the windows host from linux VM server (ping 192.168.56.1)
• I can telnet the linux job server on port 3500 from the windows host side (telnet 192.168.56.101)
• Inbound & Outbound port rules added to the windows host: 40000-65535
• ICMPv4 Inbound and outbound windows firewall host rules added for communication on all ports
• linux server iptables default config set to accept any connection for which it does not find in the rules:
  • Chain INPUT (policy ACCEPT), Chain FORWARD (policy ACCEPT), Chain OUTPUT (policy ACCEPT)

there is also in the rules(-A INPUT -p icmp -j ACCEPT,-A FORWARD -p icmp -j ACCEPT)

Wireshark(network sniffer) shows that there is an issue of communication between the designer and server: