Re: Rewrite MAC-adr on outgoing packages?
On Wed, Jan 24, 2001 at 08:40:51AM +0200, Michael Wood wrote:
> Hi
>
> On Tue, Jan 23, 2001 at 10:01:55PM +0100, Lars Hallberg wrote:
> > What I want to do is simple:
> >
> > All packeges leaving my eth0 interface shuld have the MAC-
> > adress of my eth0-card. Regardles if they is orginating att
> > another machine and only routed trhu this machine (who is a
> > gateway).
>
> Unless I misunderstand how you have your network set up, all
> packets getting to your radiomodem get there via your eth0, in
> which case they _will_ have the same MAC address!
> >
[snip]
>
> You have something like this, right?
Slightly edited:
[box.3]--+ allot
| 1 0 |
[box.7]--+--[linux]--[radiomodem]--+--[something]--[Internet]
| .2 /link .1
[box.8]--+
> Since MAC addresses are only a way for machines on _local_
> networks to talk to each other, all packets going from or
> through your linux box to the radiomodem will have the MAC
> address of your linux box' eth0.
Yeh, I like to beleve that. But it seams the linux box is
'transparent' to some pakages (arp among others, probobly all
broadkasting pakages). They get pased thru the linuxbox as is,
with ther MAC-adresses unchanged. I don't know what this
trafik is good for, exept for ARP, in witch case the linuxbox
eth0 MAC-adress is the only one that shuld leave my network
(whell, that gose fore any pakage, as nothing can get in
on any other MAC-address, and the radiomodem might reconfigure
to that MAC-address, stoping all trafik to my subnet untill
it reconfigure again after several houres :-( ).
> By the way, you shouldn't need proxyarp, unless box1, box2,
> box3, linux and radiomodem are all on the same subnet. If that
> is the case, then the whole point of proxyarp is to hand out one
> MAC address for all machines in that subnet when it gets ARP
> requests for them. So, if something weird _was_ happening,
> proxyarp should fix it.
Yes it do, but ther seams to be more pakages geting thru with
the wrong mac. I cant se the outside view of my pakages myself
so I can't tell realy how much, but my ISP say they exist :-(
> If you have everything on the same subnet, you could try
> subnetting further or using private IPs on the internal network
> and use NAT (IP Masqerading).
I prefere to have all boxes have ther real IP-number, it
simplifice some things.
Erlier I had a few random IP-numbers, now I do have a
255.255.255.240 subnet. But my .1 addres is upstrem
whith my ISP and handels routing in and out of my machine.
I have to find out more aboute this, it's some kind of
ISP independet IP-numbers (newer herd about them before
i got them). Posably I can get the upstream .1 to route
everything thru my .2. Then the upstream ethernet shuld
newer ask for anithing but .2, allowing me to stop ARP
from geting thru my machine at all. Address .2 to .14 is
useable on my net.
Are You saying that if I configure eth0 and eth1 as being
different subnet, broadcast ethernet pakages will not any
more be sent betwine them. Is there any firewall roules
to stop *all* brodkasting from coming thru?
> > I'l be happy to remove that excuse ;-)
> [snip]
>
> I don't suppose it's possible to have just the linux box
> connected up for a while to see if the link still hangs?
Not realy, somtimes it is up for thre months, then it hangs
randomly, somtimes more than one time each week, then
randomly stayes up for a while again (smells like windows).
For a short while (a long time ago) it did hang daily, but
then the log showed some strange stuff, so that was probably
a completly different matter (some atac or ilconfigured
experiment in the surounding net i supose). My Debian box
have newer had any problems, but it might ben protected
from atacs by the radiomodem hanging and stoping the
connection :-/
Thanks /Lars
--
Lars Hallberg Micro++ www.micropp.se/
Freeware * C/C++ * Python * Linux * Debian * HTML * Javascript
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