Instruction manual

UltraLink 2 DVI Installation and Operation Manual 45
IP Network Mask (IPv4 only):
The IP Network Mask field contains the subnet mask for the unit in an IPv4 environment. There is no
equivalent field for IPv6.
IP Gateway (IPv4 and IPv6):
The IP Gateway field stores the IP address of the router or other device that acts a gateway to the internet.
When the gateway address is not entered, the unit can still be accessed from within the LAN. However, for the
unit to access resources outside the LAN, such as an NTP server on the internet for Time & Date
Configuration, the gateway address must be entered.
VNC Port:
The VNC Port field contains the network port number used for VNC connections to the UL2-DVI. The standard
port for VNC connections is 5900. The field is populated with this number by default. This will work for most
situations, and it should only be changed if there is a conflict with existing network settings. If the VNC port is
changed from the default, it will be necessary to enter the new port number along with the IP address in the
RealVNC Viewer IP Connection Screen (Figure 11) in the form ip_address:new_vnc_port. For example, if the
unit has the IP address of 192.168.0.58, and the VNC port has been changed to 1234, enter the IP address of
192.168.0.58:1234. Otherwise, the RealVNC Viewer will to attempt to connect at VNC default port 5900. Since
the unit is monitoring VNC connection requests on the new port, it will not respond to the connection request. It
should be noted that the VNC port is applicable only to the RealVNC Viewer, and not the Java VNC Viewer.
HTTP Port (0=disabled):
The HTTP Port field holds the network port number for HTTP or web browser connections. It affects
connections which use the Java VNC Viewer. The default port for HTTP connections is 80, and it should only
be changed if there is a conflict within existing network settings. Unlike the VNC Port, the HTTP port can be set
to 0 to disable connections through a web browser. However, this should be avoided, since firmware upgrade
of the unit is performed through a web browser connection, as described in the Firmware Upgrade section of
the manual. If the HTTP port is changed from the default of 80, a connection attempt from the web browser
should include the new port number in the IP address in the form ip_address:new_http_port.
IP Access Control:
The IP Access Control field allows the administrator to specify ranges of IP addresses which are allowed
access to the unit. The administrator can also deny access to IP addresses within the allowed ranges. The
default setting for this field, +0.0.0.0/0.0.0.0, allows all IP addresses access to the unit. This feature should be
used with caution, because it is possible to deny access to everyone. If that occurs, a reset to factory default
settings will be required.
Setting up IP Access Control
Each entry in the Access Control list which is preceded by a + specifies a range of addresses that are allowed
access to the unit. Entries preceded by a – are IP address ranges which are denied access. When setting up
the IP Access Control list, all the ranges of IP addresses to be granted access should be higher in the list than
the IP address ranges to be denied access. This is because once a range of addresses is denied access, it is
not possible to then make exceptions for particular addresses within that range.
Figure 58. IP Access Control Field