Tech FAQ

Scan process very slow

The performance of a scan depends on various aspects.

• Several port scanners were activated concurrently.

  If your are using a individual Scan Config please take care to select only a single port scanner in the famility "Port Scanner". Of course "Ping Host" can still be activated.

• Unused IP addresses are scanned very time-consuming.

  In a first phase for each IP address it is detected whether a active system is present. In case it is not, this IP will not be scannned. Firewalls and other systems can prevent a sucessful detection. The NVT "Ping Host" (1.3.6.1.4.1.25623.1.0.100315) offers to fine-tune detection.

On scanned target systems appears a VNC dialog

When testing port 5900 or configured VNC port, a window appears on scanned target system that asks the user whether to allow the connection. This was observed for UltraVNC Version 1.0.2.

Solution: Exclude port 5900 or other configured VNC port from target specification. Alternatively upgrade to a newer version of UltraVNC would help (UltraVNC 1.0.9.6.1 only uses baloons to inform users).