ZyWALL 35 User’s Guide
298
Chapter 17 Network Address Translation (NAT)
17.1.5 Port Restricted Cone NAT
Port restricted cone NAT maps all outgoing packets from an internal IP address and port to a
single IP address and port on the external network. In the following example, the ZyWALL
maps the source address of all packets sent from internal IP address
1
and port
A
to IP address
2
and port
B
on the external network. A host on the external network (IP address
3
and Port
C
for example) can only send packets to the internal host if the internal host has already sent a
packet to the external host’s IP address and port.
A server with IP address
1
and port
A
sends packets to IP address
3
, port
C
and IP address
4
,
port
D
. The ZyWALL changes the server’s IP address to
2
and port to
B
.
Since
1
,
A
has already sent packets to
3
,
C
and
4
,
D,
they can send packets back to
2
,
B
and the
ZyWALL will perform NAT on them and send them to the server at IP address
1
, port
A
.
Packets have not been sent from
1
,
A
to
4
,
E
or
5
, so they cannot send packets to
1
,
A
.
Figure 144
Port Restricted Cone NAT Example
17.1.6 NAT Mapping Types
NAT supports five types of IP/port mapping. They are:
•
One to One
: In One-to-One mode, the ZyWALL maps one local IP address to one global
IP address.
•
Many to One
: In Many-to-One mode, the ZyWALL maps multiple local IP addresses to
one global IP address. This is equivalent to SUA (i.e., PAT, port address translation),
ZyXEL's Single User Account feature (the
SUA
option).
•
Many to Many Overload
: In Many-to-Many Overload mode, the ZyWALL maps the
multiple local IP addresses to shared global IP addresses.
•
Many One to One
: In Many-One-to-One mode, the ZyWALL maps each local IP
address to a unique global IP address.
Summary of Contents for ZyXEL ZyWALL 35
Page 1: ...ZyWALL 35 Internet Security Appliance User s Guide Version 3 64 3 2005 ...
Page 2: ......
Page 38: ...ZyWALL 35 User s Guide 36 ...
Page 46: ...ZyWALL 35 User s Guide 44 ...
Page 74: ...ZyWALL 35 User s Guide 72 Chapter 2 Introducing the Web Configurator ...
Page 90: ...ZyWALL 35 User s Guide 88 Chapter 3 Wizard Setup ...
Page 100: ...ZyWALL 35 User s Guide 98 Chapter 4 LAN Screens ...
Page 106: ...ZyWALL 35 User s Guide 104 Chapter 5 Bridge Screens ...
Page 128: ...ZyWALL 35 User s Guide 126 Chapter 6 Wireless LAN ...
Page 135: ...ZyWALL 35 User s Guide Chapter 7 WAN Screens 133 Figure 47 General ...
Page 152: ...ZyWALL 35 User s Guide 150 Chapter 7 WAN Screens Figure 57 Dial Backup Setup ...
Page 158: ...ZyWALL 35 User s Guide 156 Chapter 7 WAN Screens ...
Page 166: ...ZyWALL 35 User s Guide 164 Chapter 8 DMZ Screens ...
Page 234: ...ZyWALL 35 User s Guide 232 Chapter 13 Introduction to IPSec ...
Page 275: ...ZyWALL 35 User s Guide Chapter 15 Certificates 273 Figure 129 My Certificate Details ...
Page 294: ...ZyWALL 35 User s Guide 292 Chapter 16 Authentication Server Figure 140 Local User Database ...
Page 314: ...ZyWALL 35 User s Guide 312 Chapter 17 Network Address Translation NAT ...
Page 318: ...ZyWALL 35 User s Guide 316 Chapter 18 Static Route ...
Page 324: ...ZyWALL 35 User s Guide 322 Chapter 19 Policy Route ...
Page 340: ...ZyWALL 35 User s Guide 338 Chapter 20 Bandwidth Management ...
Page 376: ...ZyWALL 35 User s Guide 374 Chapter 22 Remote Management ...
Page 390: ...ZyWALL 35 User s Guide 388 Chapter 24 Logs Screens Figure 198 Log Settings ...
Page 413: ...ZyWALL 35 User s Guide Chapter 25 Maintenance 411 Figure 220 Restart Screen ...
Page 414: ...ZyWALL 35 User s Guide 412 Chapter 25 Maintenance ...
Page 440: ...ZyWALL 35 User s Guide 438 Chapter 28 WAN and Dial Backup Setup ...
Page 456: ...ZyWALL 35 User s Guide 454 Chapter 31 DMZ Setup ...
Page 460: ...ZyWALL 35 User s Guide 458 Chapter 32 Route Setup ...
Page 470: ...ZyWALL 35 User s Guide 468 Chapter 33 Remote Node Setup ...
Page 522: ...ZyWALL 35 User s Guide 520 Chapter 39 System Information Diagnosis ...
Page 538: ...ZyWALL 35 User s Guide 536 Chapter 40 Firmware and Configuration File Maintenance ...
Page 550: ...ZyWALL 35 User s Guide 548 Chapter 42 Remote Management ...
Page 558: ...ZyWALL 35 User s Guide 556 Chapter 43 IP Policy Routing ...
Page 574: ...ZyWALL 35 User s Guide 572 Chapter 45 Troubleshooting Figure 364 Java Sun ...
Page 602: ...ZyWALL 35 User s Guide 600 Appendix C IP Subnetting ...
Page 608: ...ZyWALL 35 User s Guide 606 Appendix E PPTP ...
Page 626: ...ZyWALL 35 User s Guide 624 Appendix G Triangle Route ...
Page 656: ...ZyWALL 35 User s Guide 654 Appendix J Importing Certificates ...
Page 658: ...ZyWALL 35 User s Guide 656 Appendix K Command Interpreter ...
Page 664: ...ZyWALL 35 User s Guide 662 Appendix L Firewall Commands ...
Page 668: ...ZyWALL 35 User s Guide 666 Appendix M NetBIOS Filter Commands ...
Page 674: ...ZyWALL 35 User s Guide 672 Appendix O Brute Force Password Guessing Protection ...
Page 696: ...ZyWALL 35 User s Guide 694 Appendix Q Log Descriptions ...