Ip Filtering - Austin Hughes Electronics Cyberview NCP-1716 User Manual

3.2 IP Filtering

3.2.1 IP Filtering
The IP filtering function keeps unauthorized hosts from accessing to the IP serial console by specifying IP
filtering rules. It is important to fully understand what an IP filter is. If you don't fully understand this, you will get
unexpected results against your original plan.
The IP address/Mask specifies the host range by entering base host IP address followed by / and subnet mask.
The host IP addresses to be filtered based on the rule defined. The table below gives examples of IP address/
Mask settings.
Specified host range
Any host
192.168.1.120
192.168.1.1 ~ 192.168.1.254
192.168.0.1 ~ 192.168.255.254
192.168.1.1 ~ 192.168.1.126
192.168.1.129 ~ 192.168.1.254
The Port is a port or port range of the IP serial console which hosts try to access to.
Chain rule
The chain rule determines whether the access from the hosts is allowed or not. It can be one of the these two
values :
■
ACCEPT :
■
DROP :
When the IPCS receives a TCP packet, it will process the packet with the chain rule depicted below. The
process ordering is important; The packet will enter the chain rule 1 first, if meet the rule then take action directly,
otherwise go to chain rule 2.
access allowed
access not allowed
TCP packet
Rule 1
Yes
No
Rule 2
Yes
No
Rule ..
Yes
No
Rule n
Yes
No
Default Rule
Yes
Base Host IP address
0.0.0.0
192.168.1.120
192.168.1.0
192.168.0.0
192.168.1.0
192.168.1.128
Action 1
Action 2
Action 3
Action 4
Action 5
P.30
Chapter 3
Subnet mask
0.0.0.0
255.255.255.255
255.255.255.0
255.255.0.0
255.255.255.128
255.255.255.128