Zilog EZ80F91GA User Manual

Page 26

The ZGATE Embedded Security Development Kit

UM024502-1012

ZGATE Embedded Security Development Kit
User Manual

3. In the browser’s URL field, enter the IP address of the ZGATE Demo program’s

Ethernet interface. For example, the IP address of the Ethernet interface displayed in
the sample code above is

192.168.2.29

4. When the ZGATE Demo program home page appears, click the

TCP Port

link on the

left side of the page.

5. The TCP Port page displays TCP numbers which ZGATE is either forwarding to ZTP

or blocking from ZTP. When the TCP Port list is operating in WHITELIST FILTER-
ING Mode (default setting), port numbers listed on the page are forwarded to ZTP;
port numbers not listed are blocked from ZTP. When the TCP Port list is operating in
BLACKLIST FILTERING Mode, port numbers listed on the page are blocked from
ZTP; port numbers not listed are forwarded to ZTP. Upon initial observation, note that
TCP ports 20 and 21 (used for FTP) are forwarded, meaning that ZGATE will pass
any incoming packets destined for those ports to ZTP.

6. With the FTP ports set to Forwarding Mode, open a command prompt on your PC and

attempt to establish an FTP session to ZTP. As an example, to establish an FTP con-
nection to IP address 192.168.2.29, enter the following command at the command
prompt:

ftp 192.168.2.29

Next, log in with

anonymous

as the username and password. Performing a

dir

com-

mand shows that FTP is working. Enter the

quit

command to terminate the FTP con-

nection to ZTP.

7. Return to your browser and delete the numbers 20 and 21 from the list of TCP port

numbers. After both boxes are empty, click the

Update

button to send the changes to

ZGATE. After a moment, the web page will be redrawn with the deleted port numbers
removed from the list.

8. Switch back to the command prompt and attempt to establish another FTP connection

with ZTP, as you did in

Step 6

. This time, however, this connection will fail because

ZGATE is blocking TCP ports 20 and 21 from reaching ZTP.

9. After the FTP connection attempt times out, switch to the ZTP console program and

enter the

zg_show stats

command to display the program’s current statistics. The

output will appear similar to the following example:

[ZTP EXTF:/]>zg_show stats

ZGATE filtering enabled

ZGATE filtering statistics – packets processed by ZGATE

Ethernet IP UDP TCP

Packets received 0 481 174 15