Netopia R310 사용자 설명서

FTP sessions. To allow WAN-originated FTP sessions to a LAN-based FTP ser ver with the IP address a.b.c.d 
(corresponding to a numbered IP address such as 163.176.8.243), inser t the following input filter ahead of the 
current input filter 1:

■

Enabled: Yes

■

For ward: Yes

■

Source IP Address: 0.0.0.0

■

Source IP Address Mask: 0.0.0.0

■

Dest. IP Address: a.b.c.d

■

Dest. IP Address Mask: 255.255.255.255

■

Protocol Type: TCP

■

Source Por t Comparison: No Compare

■

Source Por t ID: 0

■

Dest. Por t Comparison: Equal

■

Dest. Por t ID: 21

Note: A similar filter could be used to permit Telnet or WWW access. Set the Dest. Por t ID to 23 for Telnet or 
80 for WWW.

Firewall: a component or set of components that restrict access between a protected network and the Internet, 
or between two networks.

Host: A workstation on the Network.

Packet: Unit of communication on the Internet.

Packet Filter: Packet filters allow or deny packets based on source or destination IP addresses, TCP or UDP 
por ts, or the TCP ACK bit.

Port: A number that defines a par ticular type of ser vice.

Filter Rule: A filter set is comprised of individual filter rules.

Filter Set: A grouping of individual filter rules.

All IP packets contain the same basic “header” information, as follows:

Source IP Address

163.176.132.18

Destination IP Address

163.176.4.27