> Symmetric: A symmetric NAT is one where all requests
from the
> same internal IP address and port, to a specific
destination IP
> address and port, are mapped to the same external
IP address and
> port. If the same host sends a packet with the
same source
> address and port, but to a different destination,
a different
> mapping is used. Furthermore, only the external
host that
> receives a packet can send a UDP packet back to
the internal host.
>
> (...)
>
> I just want to know how to setup Symmetric NAT
>
U can setup that symmetric as follow:
iptables -t nat -A POSTROUTING -p udp -s x.x.x.x --sport
aaaa -d
y.y.y.y --dport bbbb -j snat --to-source z.z.z.z
iptables -t nat -A POSTROUTING -p udp -s x.x.x.x --sport
aaaa -d
0.0.0.0 --dport bbbb -j MASQUERADE
I think that these two rules can make the service that u
want to.
At your own taste and requirements u can specify or not the
source
port and destination port.
If u do not specify that, the translation will occurs for
all ports,
but keeping your idea of one translation specific for one
specific
destination and another for other destinations.
Denis Anjos.
2007/4/19, Pedro Gonçalves <pedro.pandre gmail.com>:
> Hi Elvir
>
> Sorry if the terms I used are not familiar to
everyone.
> The types of NAT I am talking about are defined by STUN
RFC 3489
> (http://www.faqs
.org/rfcs/rfc3489.html, section 5):
> (...)
>
> Full Cone: A full cone NAT is one where all requests
from the
> same internal IP address and port are mapped to
the same external
> IP address and port. Furthermore, any external
host can send a
> packet to the internal host, by sending a packet
to the mapped
> external address.
>
> Restricted Cone: A restricted cone NAT is one where
all requests
> from the same internal IP address and port are
mapped to the same
> external IP address and port. Unlike a full cone
NAT, an external
> host (with IP address X) can send a packet to the
internal host
> only if the internal host had previously sent a
packet to IP
> address X.
>
> Port Restricted Cone: A port restricted cone NAT is
like a
> restricted cone NAT, but the restriction includes
port numbers.
> Specifically, an external host can send a packet,
with source IP
> address X and source port P, to the internal host
only if the
> internal host had previously sent a packet to IP
address X and
> port P.
>
> Symmetric: A symmetric NAT is one where all requests
from the
> same internal IP address and port, to a specific
destination IP
> address and port, are mapped to the same external
IP address and
> port. If the same host sends a packet with the
same source
> address and port, but to a different destination,
a different
> mapping is used. Furthermore, only the external
host that
> receives a packet can send a UDP packet back to
the internal host.
>
> (...)
>
> I just want to know how to setup Symmetric NAT
>
> Thanks in advance
> Pedro
>
>
> Elvir Kuric wrote:
> > Hi Pedro,
> > what is Cone? Some abbervation or what else ?
> > Please for clearability describe what you want
achieve
> > using NAT?
> >
> > Regards
> >
> > Elvir Kuric
> >
> > --- Pedro Gonçalves <pedro.pandregmail.com> wrote:
> >
> >
> >> Hello everyone
> >>
> >> I want to know *how to* setup this types of
NAT:
> >> /-Full Cone NAT/
> >> /-Restricted Cone NAT/
> >> /-Port Restricted Cone NAT/
> >> /-Symmetric NAT/
> >>
> >> Using iptables, I set all policies to
"ACCEPT" and I
> >> was able to setup
> >> two kinds of NAT:
> >> (192.168.2.170 is my "public"
address and 10.0.0.1
> >> is my "private" address
> >>
> >> /-"Full Cone NAT", with the
following rules:/
> >> iptables -t nat -A POSTROUTING -o eth0 -j
SNAT
> >> --to-source 192.168.2.170
> >> iptables -t nat -A PREROUTING -i eth0 -j DNAT
> >> --to-destination 10.0.0.1
> >>
> >>
> >> /-"Port Restricted Cone NAT", with
just a single
> >> rule:/
> >> iptables -t nat -A POSTROUTING -o eth0 -j
SNAT
> >> --to-source 192.168.2.170/
> >>
> >> /
> >> Now does anyone know how to setup Restricted
Cone
> >> NAT and Symmetric NAT?
> >>
> >> Thanks in advance
> >> Pedro
> >> //
> >>
> >>
> >>
> >
> >
> >
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>
>
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