[plug] Dumb questino on networking

[Shackleton, Kevin]

My 2 bob's worth . .

The reason Gary says you need to proxy or masquerade is that your PPP IP
number is completely different from your LAN address.

In my case I have the subnet 159.207.52.x of a Class B address space
159.207.x.x, and a leased line to the rest of the network, so my router
(at 159.207.52.1) does not need to do any virtualisation of IP
addresses, if that's the right expression.  I actually have a 3Com
router, but a Linux PC should do the same job.

K.

> ----------
> From: 	spice at q-net.net.au[SMTP:spice at q-net.net.au]
> Reply To: 	plug at linux.org.au
> Sent: 	Tuesday, 7 July 1998 15:39
> To: 	plug at linux.org.au
> Subject: 	Re: [plug] Dumb questino on networking
> 
> On Tue, 7 Jul 1998 15:17:39 +0800 (WST), you wrote:
> 
> >I have the opportunuty to replace a NT box with a linux machine, if I
> >can gt it working as a gateway, QUICKLY.
> >
> >I sugessted a talk on this some time ago.  Somebody ( I cant remember
> 
> >who) , said that it was so trivial that it was unneccesary.
> >As it is so trivial, I know that no-one will mind answering this.
> >
> >ppp is no problem.  Ethernet is no problem.  But I dont understand
> the finer point
> >of network routing.  Yes, I have compiled the kernel with
> >gateway support.  And I have set up all the routes in the table.
> >
> >Here is the table:
> >
> >Kernel routing table
> >Destination     Gateway         Genmask         Flags MSS    Window
> Use Iface
> >203.7.224.8     *               255.255.255.255 UH    1500   0
> 0 ppp0
> >192.168.0.0     *               255.255.255.0   U     1500   0
> 1 eth0
> >127.0.0.0       *               255.0.0.0       U     3584   0
> 1 lo
> >default         203.7.224.8     *               UG    1500   0
> 6 ppp0
> >
> >WIN95 machines can connect to the linux box, but when trying to
> connect 
> >to the world,  no reply is received.  The linux box can connect to
> the world,
> >so it has to be a forwarding/gateway problem.
> >
> >How can I find out where all the IP packets which are comming in
> through 
> >eth0 are going to?  They are certainly not going to the ppp0 
> >like they ought to.  I have never done this before , and I have never
> used WIN95 
> >either anyone know how to find out what's going on?
> >
> >John
> 
> John,
> 
> By the look of the IP numbers you have on the ethernet interface, you
> either need to
> 
> 1.  Run proxy software (such as socks5) 
> 
> or
> 
> 2. Use IP masquerading.
> 
> Number 2 is the best option in my opinion.  This involves compiling a
> kernel with masq support, and inserting the appropriate protocol
> modules into the kernel.  You will also need a ipfwadm line to enable
> the masquerading.  This is an example :
> 
> ipfwadm -F -a m -S 192.168.0.0/24
> 
> If you need any more help on this, please email me or call me.
> 
> regards
> 
> Gary Allpike
> 
> -- 
> Gary Allpike - spice at q-net.net.au
> System Administrator
> Q-Net Australia    http://www.q-net.net.au
> Ph: +61-8-9386 1178   Fax: +61-8-9386 8200
>