How to resolve RDP session disconnections on FLEX/ATP?

Zyxel_Cooldia

How can I resolve constant RDP session disconnections on Zyxel USG Flex 100?

If your RDP sessions are constantly disconnecting when using a Zyxel USG Flex 100 firewall but work fine when connected directly to a modem or a wireless hotspot, the issue could be related to the ICSA protection mechanism on the firewall.

To resolve this, follow these steps:

1. Access the device's command-line interface (CLI).
2. Type the following commands:

Router# configure terminal
Router(config)# firewall icsa icmp-destroy-session disable

Disabling the ICSA destroy-session feature has been known to work and prevents the RDP session interruptions.

For more information, you can refer to this resource: Why I cannot access specific websites?