Firewall tutorial, General firewall terms, Basic ip packet components – Netopia 2200 User Manual

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Firewall Tutorial

General ﬁrewall terms

☛

Note:

Breakwater Basic Firewall (see

)

does not make use of the packet filter suppor t and can be used in addition to
filtersets

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

Filter set: A grouping of individual filter rules.

Firewall: A component or set of components that restrict access between a protected net-
work 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.

Port: A number that defines a particular type of service.

Basic IP packet components

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

Source Por t

2541

Destination Por t