Juniper JUNOSE 11.2.X IP SERVICES, Configuration Manual

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NAT enables you to translate IP addresses between two address realms (for example,
between an intranet network that uses private, not publicly routable addresses and the
Internet, or between two overlapping, private networks). When incoming traffic is received,
the IP addresses are translated back for delivery within the private network.
Using NAT at the edge of your intranet provides the following advantages:
• Allows unregistered private addresses to connect to the Internet by translating those
addresses into globally registered IP addresses
•
Increases network privacy by hiding internal IP addresses from external networks
Platform Considerations
For information about modules that support NAT on ERX14xx models, ERX7xx models,
and the ERX310 Broadband Services Router:
•
See ERX Module Guide, Table 1, Module Combinations for detailed module specifications.
•
See ERX Module Guide, Appendix A, Module Protocol Support for information about the
modules that support NAT.
NOTE: The E120 and E320 Broadband Services Routers do not support configuration
of NAT.
Module Requirements
To configure NAT on ERX7xx models, ERX14xx models, and the ERX310 router, you must
install a Service Module (SM). For information about installing modules in E Series
Broadband Services Routers, see the
ERX Hardware Guide .
Unlike other line modules, SMs do not pair with corresponding I/O modules that contain
ingress and egress ports. Instead, they receive data from and transmit data to other line
modules with access to ingress and egress ports on their own associated I/O modules.
For a list of the modules that support NAT, see ERX Module Guide, Appendix A, Module
Protocol Support .
References
For more information about NAT, consult the following resources:
• RFC 2663-IP Network Address Translator (NAT) Terminology and Considerations
(August 1999)
•
RFC 2694-DNS extensions to Network Address Translators (DNS_ALG) (September
1999)
• RFC 2993-Architecture Implications of NAT (November 2000)
Copyright © 2010, Juniper Networks, Inc. 62
JunosE 11.2.x IP Services Configuration Guide