Cyclades AlterPath ACS, Command Reference Manual

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AlterPath ACS Command Reference Guide
131
Network
DNAT (nat table only)
This target is only valid in the nat table, in the PREROUTING and OUTPUT chains, and
user-defined chains which are only called from those chains. It specifies that the
destination address of the packet should be modified (and all future packets in this
connection will also be mangled), and rules should cease being examined. It takes one
option:
MASQUERADE (nat table only)
This target is only valid in the nat table, in the POSTROUTING chain. It should only be
used with dynamically assigned IP (dialup) connections: if you have a static IP address,
you should use the SNAT target. Masquerading is equivalent to specifying a mapping to
the IP address of the interface the packet is going out on, but also has the effect that
connections are forgotten when the interface goes down. This is the correct behavior
when the next dialup is unlikely to have the same interface address (and hence any
established connections are lost anyway). It takes one option:
DNAT target Description
- - to-destination <ipaddr>[-<ipaddr>][:port-port] This can specify a single new destination
IP address, an inclusive range of IP
addresses, and optionally, a port range
(which is only valid if the rule also
specifies -p tcp or -p udp). If no port
range is specified, then the destination
port will never be modified.
Table 4.12: DNAT target
Target Description
- - to-ports <port>[-<port>] This specifies a range of source ports to use, overriding the
default SNAT source port-selection heuristics (see above). This
is only valid if the rule also specifies -p tcp or -p udp).
Table 4.13: Masquerade target