Click Configuration > Firewall > Add. Set the From field as WAN and the To
1
field as DMZ. Set the Destination to the IPPBX's DMZ IP address object
(DMZ_SIP). IPPBX_DMZ is the destination because the ZyWALL applies NAT to
traffic before applying the firewall rule. Set the Access field to allow and click
OK.
Figure 140 Configuration > Firewall > Add
7.13.5 Set Up a DMZ to LAN Firewall Rule for SIP
The firewall blocks traffic from the DMZ zone to the LAN 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.
ZyWALL USG 100/200 Series User's Guide
Chapter 7 Tutorials
175