Netopia Router PN Series Instrukcja Użytkownika Pobierz pdf (Strona 155)

Security 7-13

Src. Port: The source port to match. This is the port on the sending

host that originated the packet.

D. Port: The destination port to match. This is the port on the

receiving host for which the packet is intended.

On?: Displays Yes when the ﬁlter is in effect or No when it is not.

Fwd: Shows whether the ﬁlter forwards (Yes) a packet or discards

(No) it when there’s a match.

Filtering example #1

Returning to our ﬁltering rule example from above (see page 7-9),

look at how a rule is translated into a ﬁlter. Start with the rule, then

ﬁll in the ﬁlter’s attributes:

1. The rule you want to implement as a ﬁlter is:

Block all Telnet attempts that originate from the remote host

199.211.211.17.

2. The host 199.211.211.17 is the source of the Telnet packets

you want to block, while the destination address is any IP

address. How these IP addresses are masked determines what

the ﬁnal match will be, although the mask is not displayed in

the table that displays the ﬁlter sets (you set it when you create

the ﬁlter). In fact, since the mask for the destination IP address

is 0.0.0.0, the address for Dest IP Addr could have been

anything. The mask for Source IP Addr must be

255.255.255.255 since an exact match is desired.

■ Source IP Addr = 199.211.211.17

■ Source IP address mask = 255.255.255.255

■ Dest IP Addr = 0.0.0.0

■ Destination IP address mask = 0.0.0.0

Note: To learn about IP addresses and masks, see Appendix B,

“Understanding IP Addressing.”

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Brak uwag

Modelli	Tipo di Documento
AN-J	Manuale Utente Audio Note AN-J User Manual, 14 pagine
AN-K	Manuale Utente Audio Note AN-K User Manual, 14 pagine
AN Speaker Stands	Manuale Utente Audio Note AN Speaker Stands User Manual, 11 pagine

Netopia Router PN Series Instrukcja Użytkownika Strona 155