BB005x Installation and Configuration Guide
►
►
►
To configure a port filter:
Click on the
Port Filters
link for the policies that you want to configure from
the
Current Firewall Policies
table.
Three Add Filter hyperlinks appear allowing three different kinds of port filters,
depending on the transport protocol that needs to be filtered: TCP, UDP or Raw
IP (any IP packet).
To add a TCP port filter:
1. Click on
Add TCP filter
2. Type in the start and end of the port range for the TCP protocol that you
want to filter, then select from the drop down list whether you want to
allow/block inbound and outbound traffic.
3. Click on
Apply
The same procedure can be followed for UDP and non-TCP/UDP filters.
To configure Validators:
1. Click on
Host Validators
under
Policy Configuration
2. Click on the
Add Host Validator
link.
3. Type the IP address that you want to block access from in the
Host IP
Address
text box.
4. Type the IP mask address in the
Host Subnet Mask
box
5. Select the direction of traffic that you want to filter from the
Direction
drop down box.
6. Click
Apply.
You should now save the configuration and restart the BB005x.
To delete a validator, click on the
Delete Host Validator
hyperlink on the
Configure Validator
page. Then click on
Delete Host Validator
on the
Confirmation
page.
Triggers and Application Layer Gateways:
Many network applications can encounter difficulties while trying to operate
across a NAT firewall system. Certain applications require, at times, the
temporary opening of a secondary connection in order to function properly. This
can be done manually before the application is launched but then the
connection will stay open until it is closed manually, which will create a serious
security risk. Another obstacle is the fact that some applications often embed
the IP address of the host in the payload of the IP packet. Since NAT normally
51
