Security Triggers
74
Models 2603, 2621, and 2635 User Manual
7
• Security
2.
Enter
1
(for ICMP) in the Protocol Number field.
3.
Set both
Inbound
and
Outbound
for
Allow
. (See
figure 50
.)
4.
Click on Create.
Figure 50. Defining ICMP port filter for ping
You can now ping between the two networks
Security Triggers
Security triggers are used to allow an application to open a secondary port in order to transport data. The most
common example is FTP. This procedure sets up a trigger on the Firewall to permit an FTP session from PC A
to PC B, but not the reverse.
5.
First, create an outbound-only portfilter for FTP and add it to the item0 policy.
6.
Following the path given in step 1 for the ping portfilter in the previous section, click on
Add TCP Filter
.
7.
The Port Range is entered as
21
for both Start and End.
8.
Set Inbound as
Block
, but Outbound as
Allow
. (See
figure 51
.)
9.
Click on
Create
.
Figure 51. Configuring TCP port filter for FTP
After configuring the FTP portfilter, you can open an ftp session from Remote to Local, however you can issue
ftp commands (e.g., login, cd, etc.). Because the trigger to permit transfer of data via FTP has not been
defined, no data can be transferred. (Data transfer occurs with the commands ls, dir, get, put commands.) The
portfilter allows an ftp control channel but does not allow the use of a secondary data channel for passing data
by ftp.
Содержание OnSite 2603
Страница 23: ...23 Chapter 2 Product Overview Chapter contents Introduction 24 Applications Overview 25...
Страница 38: ...38 Chapter 4 Ethernet LAN Port Chapter contents Introduction 39 LAN Connections 39 Ethernet Port 39...
Страница 120: ...120 Appendix C Cable Recommendations Chapter contents Ethernet Cable 121 Adapter 121...
