Zilog EZ80F91GA - Manual (Page 27)

UM024502-1012 Using the ZGATE Demo Sample Program
ZGATE Embedded Security Development Kit
User Manual
15
Packets blocked 0 175 174 3
Three TCP packets (i.e., attempts to establish an FTP connection) were blocked because of
the change made on the ZGATE TCP Port web page.
10. To reenable FTP, return to your browser and click the Add button two times to create
two empty boxes at the end of the list. In the first box, enter the number 20; in the sec-
ond box, enter the number 21. Click the
Update button.
11. Return to the command prompt on the PC and reattempt to establish an FTP connec-
tion with ZTP. This time, the connection should succeed.
12. Return to the browser and delete the number 80 from the list of TCP port numbers,
then click the Update button. This time, the web page will not refresh because TCP
port 80 is now blocked; unless the browser receives information from TCP port 80, it
will not be able to refresh the display.
13. To verify that TCP port 80 has been blocked, switch to the ZTP console program and
enter the zg_show tcp command. The output will appear similar to the following
example:
ZTP EXTF:/]>zg_show tcp
ZGATE filtering enabled
TCP filtering configuration
TCP port whitelist
{1,7,22,23,25,37,42,43,57,88,107,115,162,179,264,443,546,547,99
2,8081,20,21}
[ZTP EXTF:/]>
As you can see, port 80 was removed from the list of TCP port numbers that ZGATE
forwarded to ZTP.

14. To reenable browser access to ZTP, enter the following command on the ZTP console:
zg_config add tcp_port 80
15. Next, issue the zg_show tcp command to verify that TCP port 80 is reenabled.
16. Return to your browser one final time to refresh the web page. The browser should
again be able to retrieve pages from ZTP.
Note: