TELES VoIP Box BRI Series, Reference Manual

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4 Configuration files
VoIPBox DSL / VoIPBox BRI – version 21.0.009 Page 57
4.1.4 DSL configuration
The DSL configuration is described in Chapter 3.10 on
page 38
→
.
4.1.5 Firewall configuration
If the VoIPBox DSL / VoIPBox BRI is running in a DMZ (Demili-
tarized zone (computing)) the firewall must be activated in the
ip.cfg
(see Chapter 4.1.5 on page 57
→)
.
The firewall used on VoIPBox DSL / VoIPBox BRI is iptables.
The documentation is freely available on the internet . Only
the table filter is used in the
ip.cfg
. Outgoing traffic is allowed
unless otherwise specified. Incoming and forwarded traffic is
dropped unless otherwise specified.
The options used in Example 4.5
→
are listed in Table 4.4
→
.
Table 4.4 iptable options used in Example 4.5
→
Option Description
-P INPUT DROP Policy for the chain (INPUT, OUTPUT, FORWARD) used if no other
filter rule is defined. The action used in this case is DROP. For the
other rules, use the action ACCEPT.
-A INPUT Policy added to the INPUT chain.
-d <destination IP> This policy is only true for packets with the given destination IP ad-
dress.
-s <source IP> This policy is only true for packets from the given source IP ad-
dress.
This option is not used in the example but if the source is known
use this option for more security.
-i <interface> This policy is only true for packages used the given IP interface. (lo
– local loop interface, ppp0 – the first IP interface)
-p <protocol> This policy is only true for the given IP protocol (UDP, TCP).