Pptp And Gre Tunneling Through Nat; Packet Discard Rules; Before You Begin - Juniper IP SERVICES - CONFIGURATION GUIDE V 11.1.X Configuration Manual

JUNOSe 11.1.x IP Services Configuration Guide

PPTP and GRE Tunneling Through NAT

You can configure NAT traversal support for GRE flows using simple translations
(Basic NAT). Because PPTP uses an enhanced GRE encapsulation for the PPP payload,
configuring for GRE flows also supports NAT traversal for PPTP tunnels.
NOTE: Neither port translation (NAPT) nor Firewall traversal for GRE packets is
supported for GRE flows.
When configured, the following types of translations are supported for GRE and PPTP
tunnels:

Packet Discard Rules

For all supported types of traffic (TCP, UDP, ICMP, and GRE), NAT discards packets
in the following cases:
In addition, NAT discards GRE packets under the following conditions:

Before You Begin

You can configure certain IP interfaces to participate in Network Address Translation.
This chapter discusses how to configure NAT to function for certain IP interfaces.
For information about general IP interface configuration, see Configuring IP in JUNOSe
IP, IPv6, and IGP Configuration Guide.
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PPTP and GRE Tunneling Through NAT

Inside source static simple translations (inbound and outbound)
Outside source static simple translations (inbound and outbound)
Inside source dynamic simple translations (inbound and outbound)
Outside source dynamic simple translations (inbound and outbound)
Combinations of the preceding translations (for example, twice NAT)
When the translation table is full (that is, no more entries can be added).
When the address pool is exhausted for outbound packets with inside source
dynamic translation.
When no match can be found for the destination addresses of inbound packets.
When the address pool is exhausted for inbound packets with outside source
dynamic translation.
When the GRE packets match an NAPT rule.
When Firewall is functioning.