ZyXEL Communications Corporation 5VZ-A2011 Manuel D’Utilisation
Chapter 11 Firewall
CellPipe 7130 RG User’s Guide
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active. If the person configuring or managing the computer is not careful, a hacker
could attack it over an unprotected port.
could attack it over an unprotected port.
Some of the most common IP ports are:
Default Filtering Policies
Filtering rules are grouped based on the direction of travel of packets to which
they apply.
they apply.
The default rule for incoming traffic blocks all incoming connections from the WAN
to the LAN. If you wish to allow certain WAN users to have access to your LAN,
you will need to create custom rules to allow it.
to the LAN. If you wish to allow certain WAN users to have access to your LAN,
you will need to create custom rules to allow it.
Note: If you configure filtering rules without a good understanding of how they work,
you might inadvertently introduce security risks to the firewall and to the
protected network. Make sure you test your rules after you configure them.
protected network. Make sure you test your rules after you configure them.
These custom rules work by comparing the Source IP address, Destination IP
address and IP protocol type of network traffic to rules set by the administrator.
Your customized rules take precedence and override the CellPipe 7130 RG’s
default rules.
address and IP protocol type of network traffic to rules set by the administrator.
Your customized rules take precedence and override the CellPipe 7130 RG’s
default rules.
Denial of Service (DoS)
Denial of Service (DoS) prevents customers, users, clients or other computers
from accessing data on a computer. This is usually accomplished by interrupting or
overwhelming the computer with bad or excessive information requests.
from accessing data on a computer. This is usually accomplished by interrupting or
overwhelming the computer with bad or excessive information requests.
Table 51 Common IP Ports
21
FTP
53
DNS
23
Telnet
80
HTTP
25
SMTP
110
POP3