Zyxel ZyWALL USG 2000 [119/150] What can go wrong

Chapter 5 Managing Traffic

ZyWALL USG 20-2000 User’s Guide

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5.7.2.4 Set Up a DMZ to LAN Firewall Rule for SIP

The firewall blocks traffic from the DMZ zone to the LAN1 zone by default so you need to create a

firewall rule to allow the IPPBX to send SIP traffic to the SIP clients on the LAN.

1 Click Configuration > Firewall > Add. Set the From field as DMZ and the To field as LAN1. Set

the Destination to the IPPBX’s DMZ IP address object (DMZ_SIP). Set the

Source to

IPPBX_DMZ. Leave the Access field to allow and click OK.

5.7.3 What Can Go Wrong

• The ZyWALL checks the firewall rules in order and applies the first firewall rule the traffic

matches. If traffic matches a rule that comes earlier in the list, it may be unexpectedly blocked.

• The ZyWALL does not apply the firewall rule. The ZyWALL only apply’s a zone’s rules to the

interfaces that belong to the zone. Make sure the WAN interface is assigned to WAN zone.