Chapter 11 Firewall
ZyWALL 5/35/70 Series User’s Guide
254
• has a static IP address,
• or you configure a static DHCP entry for it so the ZyWALL always assigns it the same IP
address (see
Section 6.8 on page 155
for information on static DHCP).
Now you configure a LAN to WAN firewall rule that allows IRC traffic from the IP address of
the CEO’s computer (192.168.1.7 for example) to go to any destination address. You do not
need to specify a schedule since you want the firewall rule to always be in effect. The
following figure shows the results of your two custom rules.
Figure 141
Limited LAN to WAN IRC Traffic Example
Your firewall would have the following configuration.
• The first row allows the LAN computer at IP address 192.168.1.7 to access the IRC
service on the WAN.
• The second row blocks LAN access to the IRC service on the WAN.
• The third row is (still) the firewall’s default policy of allowing all traffic from the LAN to
go to the WAN.
The rule for the CEO must come before the rule that blocks all LAN to WAN IRC traffic. If
the rule that blocks all LAN to WAN IRC traffic came first, the CEO’s IRC traffic would
match that rule and the ZyWALL would drop it and not check any other firewall rules.
11.6 Asymmetrical Routes
If an alternate gateway on the LAN has an IP address in the same subnet as the ZyWALL’s
LAN IP address, return traffic may not go through the ZyWALL. This is called an
asymmetrical or “triangle” route. This causes the ZyWALL to reset the connection, as the
connection has not been acknowledged.
You can have the ZyWALL permit the use of asymmetrical route topology on the network
(not reset the connection).
Table 68
Limited LAN to WAN IRC Traffic Example
#
SOURCE
DESTINATIO
N
SCHEDULE
SERVICE
ACTION
1
192.168.1.7
Any
Any
IRC
Allow
2
Any
Any
Any
IRC
Drop
Default
Any
Any
Any
Any
Allow
Summary of Contents for ZyWALL 35 Series
Page 2: ......
Page 8: ...Safety Warnings ZyWALL 5 35 70 Series User s Guide 8 ...
Page 52: ...List of Tables ZyWALL 5 35 70 Series User s Guide 52 ...
Page 54: ...54 ...
Page 60: ...Chapter 1 Getting to Know Your ZyWALL ZyWALL 5 35 70 Series User s Guide 60 ...
Page 86: ...Chapter 2 Introducing the Web Configurator ZyWALL 5 35 70 Series User s Guide 86 ...
Page 140: ...Chapter 4 Tutorials ZyWALL 5 35 70 Series User s Guide 140 ...
Page 146: ...Chapter 5 Registration ZyWALL 5 35 70 Series User s Guide 146 ...
Page 148: ...148 ...
Page 160: ...Chapter 6 LAN Screens ZyWALL 5 35 70 Series User s Guide 160 ...
Page 173: ...Chapter 8 WAN Screens ZyWALL 5 35 70 Series User s Guide 173 Figure 93 NETWORK WAN General ...
Page 202: ...Chapter 8 WAN Screens ZyWALL 5 35 70 Series User s Guide 202 ...
Page 212: ...Chapter 9 DMZ Screens ZyWALL 5 35 70 Series User s Guide 212 ...
Page 242: ...242 ...
Page 274: ...Chapter 11 Firewall ZyWALL 5 35 70 Series User s Guide 274 ...
Page 294: ...Chapter 13 Configuring IDP ZyWALL 5 35 70 Series User s Guide 294 ...
Page 320: ...Chapter 15 Anti Spam ZyWALL 5 35 70 Series User s Guide 320 ...
Page 342: ...Chapter 16 Content Filtering Screens ZyWALL 5 35 70 Series User s Guide 342 ...
Page 350: ...Chapter 17 Content Filtering Reports ZyWALL 5 35 70 Series User s Guide 350 ...
Page 424: ...Chapter 19 Certificates ZyWALL 5 35 70 Series User s Guide 424 ...
Page 430: ...430 ...
Page 448: ...Chapter 21 Network Address Translation NAT ZyWALL 5 35 70 Series User s Guide 448 ...
Page 474: ...Chapter 24 Bandwidth Management ZyWALL 5 35 70 Series User s Guide 474 ...
Page 514: ...Chapter 26 Remote Management ZyWALL 5 35 70 Series User s Guide 514 ...
Page 533: ...533 PART V Reports Logs and Maintenance Reports 535 Logs Screens 547 Maintenance 575 ...
Page 534: ...534 ...
Page 551: ...Chapter 31 Logs Screens ZyWALL 5 35 70 Series User s Guide 551 Figure 334 LOGS Log Settings ...
Page 592: ...Chapter 32 Maintenance ZyWALL 5 35 70 Series User s Guide 592 ...
Page 594: ...594 Troubleshooting 751 Product Specifications 757 ...
Page 602: ...Chapter 33 Introducing the SMT ZyWALL 5 35 70 Series User s Guide 602 ...
Page 622: ...Chapter 35 WAN and Dial Backup Setup ZyWALL 5 35 70 Series User s Guide 622 ...
Page 628: ...Chapter 36 LAN Setup ZyWALL 5 35 70 Series User s Guide 628 ...
Page 634: ...Chapter 37 Internet Access ZyWALL 5 35 70 Series User s Guide 634 ...
Page 638: ...Chapter 38 DMZ Setup ZyWALL 5 35 70 Series User s Guide 638 ...
Page 642: ...Chapter 39 Route Setup ZyWALL 5 35 70 Series User s Guide 642 ...
Page 658: ...Chapter 41 Remote Node Setup ZyWALL 5 35 70 Series User s Guide 658 ...
Page 662: ...Chapter 42 IP Static Route Setup ZyWALL 5 35 70 Series User s Guide 662 ...
Page 700: ...Chapter 45 Filter Configuration ZyWALL 5 35 70 Series User s Guide 700 ...
Page 738: ...Chapter 50 Remote Management ZyWALL 5 35 70 Series User s Guide 738 ...
Page 746: ...Chapter 51 IP Policy Routing ZyWALL 5 35 70 Series User s Guide 746 ...
Page 766: ...766 ...
Page 770: ...Appendix A Hardware Installation ZyWALL 5 35 70 Series User s Guide 770 ...
Page 780: ...Appendix C Removing and Installing a Fuse ZyWALL 5 35 70 Series User s Guide 780 ...
Page 802: ...Appendix D Setting up Your Computer s IP Address ZyWALL 5 35 70 Series User s Guide 802 ...
Page 816: ...Appendix F Common Services ZyWALL 5 35 70 Series User s Guide 816 ...
Page 852: ...Appendix J Importing Certificates ZyWALL 5 35 70 Series User s Guide 852 ...
Page 856: ...Appendix K Legal Information ZyWALL 5 35 70 Series User s Guide 856 ...
Page 862: ...Appendix L Customer Support ZyWALL 5 35 70 Series User s Guide 862 ...