Chapter 9 Firewall Configuration
P-793H User’s Guide
133
Figure 58
“Triangle Route” Problem
9.5.2 Solving the “Triangle Route” Problem
You can have the ZyXEL Device allow triangle route sessions. However this can allow traffic
from the WAN to go directly to a LAN computer without passing through the ZyXEL Device
and its firewall protection.
Another way to solve the triangle route problem is to use IP alias. IP alias allows you to
partition your network into logical sections over the same Ethernet interface. Your ZyXEL
Device supports up to three logical LAN interfaces with the ZyXEL Device being the gateway
for each logical network. By putting your LAN and Gateway
A
in different subnets, all
returning network traffic must pass through the ZyXEL Device to your LAN. The following
steps describe such a scenario.
1
A computer on the LAN initiates a connection by sending a SYN packet to a receiving
server on the WAN.
2
The ZyXEL Device
reroutes the packet to Gateway A, which is in Subnet 2.
3
The reply from the WAN goes to the ZyXEL Device.
4
The ZyXEL Device then sends it to the computer on the LAN in Subnet 1.
Figure 59
IP Alias
9.6 General Firewall Policy
Click
Security > Firewall
to display the following screen. Activate the firewall by selecting
the
Active Firewall
check box as seen in the following screen.
Summary of Contents for G.SHDSL.bis 4-port Security Gateway P-793H
Page 2: ......
Page 7: ...Safety Warnings P 793H User s Guide 7 This product is recyclable Dispose of it properly ...
Page 8: ...Safety Warnings P 793H User s Guide 8 ...
Page 30: ...List of Figures P 793H User s Guide 30 ...
Page 36: ...List of Tables P 793H User s Guide 36 ...
Page 38: ...38 ...
Page 68: ...Chapter 4 Point to 2 point Configuration P 793H User s Guide 68 ...
Page 70: ...70 ...
Page 114: ...Chapter 7 Network Address Translation NAT Screens P 793H User s Guide 114 ...
Page 116: ...116 ...
Page 152: ...Chapter 10 Content Filtering P 793H User s Guide 152 ...
Page 180: ...Chapter 12 Static Route P 793H User s Guide 180 ...
Page 194: ...Chapter 14 Dynamic DNS Setup P 793H User s Guide 194 ...
Page 216: ...Chapter 16 Universal Plug and Play UPnP P 793H User s Guide 216 ...
Page 217: ...217 PART IV Maintenance System 219 Logs 225 Tools 229 Diagnostic 235 ...
Page 218: ...218 ...
Page 224: ...Chapter 17 System P 793H User s Guide 224 ...
Page 234: ...Chapter 19 Tools P 793H User s Guide 234 ...
Page 238: ...238 ...
Page 244: ...Chapter 21 Introducing the SMT P 793H User s Guide 244 ...
Page 248: ...Chapter 22 General Setup P 793H User s Guide 248 ...
Page 256: ...Chapter 23 WAN Setup P 793H User s Guide 256 ...
Page 262: ...Chapter 24 LAN Setup P 793H User s Guide 262 ...
Page 278: ...Chapter 27 Static Route Setup P 793H User s Guide 278 ...
Page 308: ...Chapter 30 Filter Configuration P 793H User s Guide 308 ...
Page 310: ...Chapter 31 SNMP Configuration P 793H User s Guide 310 ...
Page 312: ...Chapter 32 System Password P 793H User s Guide 312 ...
Page 322: ...Chapter 33 System Information Diagnosis P 793H User s Guide 322 ...
Page 352: ...Chapter 37 Schedule Setup P 793H User s Guide 352 ...
Page 360: ...360 ...
Page 366: ...Appendix B Wall mounting Instructions P 793H User s Guide 366 ...
Page 400: ...Appendix F IP Address Assignment Conflicts P 793H User s Guide 400 ...
Page 404: ...Appendix G Common Services P 793H User s Guide 404 ...
Page 432: ...Appendix K Legal Information P 793H User s Guide 432 ...
Page 443: ...Index P 793H User s Guide 443 ...
Page 444: ...Index P 793H User s Guide 444 ...