Auto IP configuration

Auto IP configuration

[Wei Ming Long]

Hi everyone,
I am thinking of setting up a wireless lan and hope to use my laptop as
wireless client with dynamic ip address, using dhcp & running netfilter on the
gateway. I use my laptop at office with a static ip address and configured
proxy server. My question is: Can netfilter do nat or packet filtering based
on mac address so that I do not have to change my network configurations each
time my network environment changes. 

Scenario 1 - With only my laptop

Internet ------------- Linux Gateway (ip address = 192.1681.1, Netfilter +
DHCP + Squid) -------------- My laptop A (ip address = 192.168.1.1)(dynamic)

Scenario 2 - With my laptop & a friend's laptop

Internet ------------- Linux Gateway +-------------- My laptop A (ip address
= 192.168.1.1) (dynamic)
                                  +
                                   |
                                   |
                                   |
                        Friend's laptop B (ip address = 172.16.1.1)
(static),

All help greatly appreciated. Thanks.

Best regards
Matthew

auto ip configuration

[Unknown]

dear list,

you know about people, which have some static ip configuration on their
notebooks. they would like to connect to a smart gateway
without the need to change anything. 

I would ask you whether this is possible to implement such a gateway
using netfilter.

I alredy build a working example with some tools and scripting
but it isn't really performant and it have a lot of "design errors".
Simple speaking it is a farpd running box, where all incoming requests
are logged through the bridging code. The Syslog output is piped
into a script and the requested ip is assigned to the lan interface.
Evil thing ;-)

I would preffer something like inverse SNAT/MASQUERADE.
The difference would be, that:
	it applys to PREROUTING
	it does mapping from a big subnet (maybe 0/0) to a singe address or a
range of addresses.

The farpd would point all clients to the gateway.
Having rp_filter disabled all misconfigured packets incoming on a lan
interface would be translated into a valid ip address.
Then the usual routing would take place.
The response packets would be back-natted into the clients idea of the
gateway address.

Would please someone give me a pointer.
Am I completly wrong with this?

regards
jaroslaw

Re: auto ip configuration

[Unknown]

hello,

please could you developer have a look at the description below
and tell whethet there is the way to make it?

example scenario:

client host-------------------gateway--------------------internet
10.0.0.1-----------192.168.0.1_______213.39.239.123-------------->>>

It would be nice to have a iptables Target acting like SNAT/MASQUERADE
but in the PREROUTING table doing the inverse job.
The goal shoud be to translate not valid ip-addresses into valid local
address space, so user not being able to change their ip-setting could
surf the net.

I am not experienced in kernel hacking so i would preffer to donate for
your work if it is something no one would have but me.

thanks in advance
jaroslaw


> dear list,
> 
> you know about people, which have some static ip configuration on their
> notebooks. they would like to connect to a smart gateway
> without the need to change anything. 
> 
> I would ask you whether this is possible to implement such a gateway
> using netfilter.
> 
> I alredy build a working example with some tools and scripting
> but it isn't really performant and it have a lot of "design errors".
> Simple speaking it is a farpd running box, where all incoming requests
> are logged through the bridging code. The Syslog output is piped
> into a script and the requested ip is assigned to the lan interface.
> Evil thing ;-)
> 
> I would preffer something like inverse SNAT/MASQUERADE.
> The difference would be, that:
> 	it applys to PREROUTING
> 	it does mapping from a big subnet (maybe 0/0) to a singe address or a
> range of addresses.
> 
> The farpd would point all clients to the gateway.
> Having rp_filter disabled all misconfigured packets incoming on a lan
> interface would be translated into a valid ip address.
> Then the usual routing would take place.
> The response packets would be back-natted into the clients idea of the
> gateway address.
> 
> Would please someone give me a pointer.
> Am I completly wrong with this?
> 
> regards
> jaroslaw
> 

RE: auto ip configuration

[Gary W. Smith]

Longshot but I think that it's called DHCP.  Otherwise you would have to change something somewhere each time you plug up your laptop.
 
Gary

________________________________

From: netfilter-devel-bounces@lists.netfilter.org on behalf of Unknown
Sent: Wed 6/22/2005 1:53 PM
To: nf-devel
Subject: auto ip configuration



dear list,

you know about people, which have some static ip configuration on their
notebooks. they would like to connect to a smart gateway
without the need to change anything.

I would ask you whether this is possible to implement such a gateway
using netfilter.

I alredy build a working example with some tools and scripting
but it isn't really performant and it have a lot of "design errors".
Simple speaking it is a farpd running box, where all incoming requests
are logged through the bridging code. The Syslog output is piped
into a script and the requested ip is assigned to the lan interface.
Evil thing ;-)

I would preffer something like inverse SNAT/MASQUERADE.
The difference would be, that:
        it applys to PREROUTING
        it does mapping from a big subnet (maybe 0/0) to a singe address or a
range of addresses.

The farpd would point all clients to the gateway.
Having rp_filter disabled all misconfigured packets incoming on a lan
interface would be translated into a valid ip address.
Then the usual routing would take place.
The response packets would be back-natted into the clients idea of the
gateway address.

Would please someone give me a pointer.
Am I completly wrong with this?

regards
jaroslaw

RE: auto ip configuration

[Unknown]

hi Gary,

i heard about DHCP, but a lot of people out there does not.
they haven't any idea of ip. They admins configured they computers
not to use dhcp but STATIC ip configuration.
In such a case it would be nice to have a feature like described below.

regards
jaroslaw

Am Mittwoch, den 22.06.2005, 13:55 -0700 schrieb Gary W. Smith:
> Longshot but I think that it's called DHCP.  Otherwise you would have to change something somewhere each time you plug up your laptop.
>  
> Gary
> 
> ________________________________
> 
> From: netfilter-devel-bounces@lists.netfilter.org on behalf of Unknown
> Sent: Wed 6/22/2005 1:53 PM
> To: nf-devel
> Subject: auto ip configuration
> 
> 
> 
> dear list,
> 
> you know about people, which have some static ip configuration on their
> notebooks. they would like to connect to a smart gateway
> without the need to change anything.
> 
> I would ask you whether this is possible to implement such a gateway
> using netfilter.
> 
> I alredy build a working example with some tools and scripting
> but it isn't really performant and it have a lot of "design errors".
> Simple speaking it is a farpd running box, where all incoming requests
> are logged through the bridging code. The Syslog output is piped
> into a script and the requested ip is assigned to the lan interface.
> Evil thing ;-)
> 
> I would preffer something like inverse SNAT/MASQUERADE.
> The difference would be, that:
>         it applys to PREROUTING
>         it does mapping from a big subnet (maybe 0/0) to a singe address or a
> range of addresses.
> 
> The farpd would point all clients to the gateway.
> Having rp_filter disabled all misconfigured packets incoming on a lan
> interface would be translated into a valid ip address.
> Then the usual routing would take place.
> The response packets would be back-natted into the clients idea of the
> gateway address.
> 
> Would please someone give me a pointer.
> Am I completly wrong with this?
> 
> regards
> jaroslaw
> 
> 
> 
>