General Issues


When I run NCF, some applications fail to work. Why?

Check whether you have blocked the application unknowingly.

To do this:

  1. From the NCF menu select Options > Application. The Application Tab is displayed.

  2. Verify whether the application is in the Blocked Applications list.

  3. (If so) Drag-and-drop it either to the list of Trusted Applications or Partially Allowed Applications.


My attack detection event log gives information about a portscan event. What should I do?

A portscan is initiated by a remote host to determine the open ports on the local system. Usually, this is done by malicious attackers prior to staging an attack on the local system or prior to hosting a distributed attack from the local system. NCF detects these portscans and filters them out.However, at times it may suspect (incorrectly) a trusted host's connection request as an attack, also known as a false positive, and log the information in the Information Panel.The pattern of port numbers scanned will help you to differentiate a false positive from a true alert. But a less familiar user may choose to either notify his network administrator about the alert, or simply ignore the logged information as the system is protected by NCF in any case.


Certain areas on the web pages I browse display the terms AD_IMG, AD_SIZE, and AD. What do they mean?

These are instances of removed advertisements using the Advertisement Blocking option in NCF. See Ad Blocking. The space from where you have removed advertisements will show one of the above terms.


After installing NCF, I tried to ping the machine from outside, but it is not accessible. Why?

By default your system is configured to the stealth mode. In order to ping, you have to enable In and Out options for both Echo Request and Echo Reply.

To do this:

  1. From the NCF menu, select Options > System. Options dialog box is displayed.

  2. Click Settings in the ICMP section. The ICMP window is displayed.

  3. Keep In and Out options checked for both Echo Reply and Echo Request message types.

WARNING:  

Enabling In and Out options for both Echo Request and Echo Reply can expose the system identity to Internet.


I tried to block certain sites using the content filtering option, but NCF fails to block the content. Why?

You will encounter this problem if you have typed http:// along with the URL of the site you want to filter in the Options (Blocked Sites Tab) window. See Content Blocking for details.

Type only the name of the site you are filtering.Example: http://www.abcdefg.com (wrong) www.abcdefg.com (right).


I get a very delayed response while accessing some http:// sites, why is this?

If the site is redirecting the request to https://, specify the https:// URL directly instead of http:// URL.


What should I do when the message 'Handle is Invalid' pops up?

Exit and Shutdown NCF. Then restart it to resolve this.

After Restart, if the message continues to pop up, check whether your system meets the minimum memory requirements. See Minimum System Requirements for details.


Sometimes, at the Startup, my system fails to communicate with the network. Is this NCF related?

Check if this is related to NCF in the following ways:


For no apparent reason, my system runs out of hard disk space. Is this NCF related?

Check if this is NCF related.

To do this, verify the size of the log database (op_data.mdb). If it has taken a substantial amount of hard disk space (for example, more than 100MB) clear it.

To do this:

  1. From the NCF main menu click Tools > Novell Client Firewall Log Viewer. Novell Client Firewall Log Viewer appears.

  2. Select File > Repair Database. The Database Repair dialog box appears.

  3. Click option Mark Database as "corrupt". On next OS startup delete file and create new.

  4. Click OK.