R
RAS Spain
After migrating to Windows 10 Build 1809 (from Build 1607), setting up sessions with the same socket (IP and Port) not working.
There is a PC with Windows 10 Build 1809 with a listening port 105. A client connects to this port with a certain IP and local Port). Then performs a SYN - PSH - FIN sequence. Then if it tries to set up a session some mili seconds later with the same socket (IP and port) the communication seems to be blocked. (right part of the Wireshark image). With Windows 10 Build 1607 the second comunication can be established (see left side of image. Wireshark indicates "TCP Port numbers reused" .
It was tried deactivating Firewall (in case the new SYN telegram is dropoup), change timeouts via "HKLM\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters" registry keys.
The session can be established again AFTER 60 seconds!!.
So far I read, here is no porblem with setting up sessions with the same ip addresses and ports, t. But... firewalls, loadbalancers, ids systems and other systems that do something active with the traffic might keep state information. Even for a little while after the session has been terminated.
Any idea which Service or system in Windows 10 Build 1809 is causing this problem?
Continue reading...
There is a PC with Windows 10 Build 1809 with a listening port 105. A client connects to this port with a certain IP and local Port). Then performs a SYN - PSH - FIN sequence. Then if it tries to set up a session some mili seconds later with the same socket (IP and port) the communication seems to be blocked. (right part of the Wireshark image). With Windows 10 Build 1607 the second comunication can be established (see left side of image. Wireshark indicates "TCP Port numbers reused" .
It was tried deactivating Firewall (in case the new SYN telegram is dropoup), change timeouts via "HKLM\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters" registry keys.
The session can be established again AFTER 60 seconds!!.
So far I read, here is no porblem with setting up sessions with the same ip addresses and ports, t. But... firewalls, loadbalancers, ids systems and other systems that do something active with the traffic might keep state information. Even for a little while after the session has been terminated.
Any idea which Service or system in Windows 10 Build 1809 is causing this problem?
Continue reading...