06 Aug 96 , Michael Thomson did fondle the keyboard and wrote to me!:
 Yowser & greets Michael!,

 >> Logically speaking, your interface is not an address, so why does it need
 >> an
 >> address allocated? You are basically saying I need 4 IP's for my 2
 >> machines.
 >> True this will work but it is not really needed. The computer is the
 >> address,
 >> it is what processes the TCP packets and protocols.

 MT> Yes, but /how/ do you get the TCP packet to go through the correct
 MT> interface?  Your Ethernet card needs to have a different address to
 MT> your PPP connection.  Dave is correct here.

Well, it appears to work of every system I've seen. Also, you must take
into consideration that mine is not a subnet system. I am running off a
type "C" system and not a type "B" system. Also, I have
no problems sending tcp packets across my ppp or internet links - except
when it exceeds a certain size in which case there is a problem with my
SanaII driver, but otherwise it appears to work.

Also, you could basically say that the ppp link has the IP of the server at
the other end - in which case, I suppose you could pretend that's 2 ip's.

 >> I look at it as if I only had a ppp link to my ISP then I would need 2
 >> addresses, one for the Amiga and one for the PPP. But this is not the
 >> case, the
 >> ppp is the same IP as my computer, it is given (in the state of dynamic
 >> connections) by the ISP and is the address used to contact any TCP
 >> related
 >> programs on my machine.

 MT> But you then need to pick an IP address for the Ethernet connection to
 MT> your Amiga. This is difficult without getting 2 permanently allocated
 MT> IP addresses from your ISP.

For the ethernet connection "to" the Amiga? Ah, you're speaking
about the PC then - yes it has it's own IP as well. I have 2 IP's, one for
the Amiga and one for the PC.

 MT> I am experiencing similar needs here to yours, we have a Linux server
 MT> and
 MT> now need to dialup as a dynamic PPP as we have lost our 24hr permanent
 MT> IP. :(

Why not dial up as a static IP? That is how my system runs. The Linux
server can easily be configured a script  to allocate a certain IP address
(a static one) during the login. Once your login name is given the script
can detect it is "you" and assign the same IP address, outside
the IP's given to the modem lines.

The server is configured to forward all mail etc to my domain etc, my ISP
is very helpful and rather smart with Linux - but then, the poor guy is
just about glued to the machine 24hrs a day ;-)

 MT> We are sorting it out, and is easy to do in theory with Linux. (all I
 MT> have to do now is tell everything on the Amiga to talk to the local
 MT> "proxy"
 MT> rather than talking to the outside world.  We are also thinking about
 MT> setting up a Firewall program on the Linux box - this will apparently
 MT> be
 MT> a much better way of doing things. There should be some available for
 MT> OS/2
 MT> or Win95. (maybe)

The firewall is ok, but can be a pain for some apps, I suggest you look
into a login script for mgetty on the server so it can assign a static IP.
If your provider is unaware of this procedure I might be able to gleam the
info from mine for you.

 >> Also, my ISP (and a few others I have seen) run extra machines for their
 >> own
 >> purposes off their server, this is usually done with ethernet cards. They
 >> only
 >> give the machine connected an IP, they don't allocate addresses to the
 >> actual
 >> ethernet connection other than to give it the machines IP.

 MT> I think you'll find that the other machines have only one interface,
 MT> and
 MT> therefore need only the one IP address. The machine(s) with the dialup
 MT> lines
 MT> will have a separate IP for each dialup line, as well as its Ethernet
 MT> address.

Mike, each machine ethernetted off the server has it's own IP address (I
won't list them here :) ) and yes each dialup line has one as well, but
that IP is assigned at login, even though it's the same one for the same
modem (ie *.*.*.100 is modem 1 etc etc), However, it can be overidden, thus
if I dial in on modem 1, my IP gets assigned *.*.*.52 and the same goes no
matter which modem I use.

I understand your point, I would need a second IP if my dialup link was
dynamic - but it isn't.

Cheers,       __
             /_/                 
            / \*icta*...

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