ZyXEL Communications 10 - Manual (Page 214)

ZyWALL 10~100 Series Internet Security Gateway
16-18 Creating Custom Rules
Step 6. Configure the Firewall IP Config screen as follows and click Apply.
Figure 16-8 Firewall IP Config Screen
Step 7. In the firewall rule configuration screen, click Add under Custom Port to open the Custom Port
Configuration screen. Configure it as follows and click Apply.