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 From:  Earl Cliffson <ecliffson at yahoo dot com>
 To:  m0n0wall at lists dot m0n0 dot ch
 Subject:  routing and proxy ARP
 Date:  Sun, 8 Feb 2004 10:26:18 -0800 (PST)
A question -  Manuel wrote "proxy ARP only causes your
ISP's router or whatever to send packets to all of
your IP addresses to your m0n0wall, even though there
is no static route on their router that tells it to do
so (because you don't have a real subnet)."

Also he wrote "It is only there to replace the
automatic IP aliasing on WAN that we used to have
before pb27."

Can someone explain the difference between IP aliasing
and proxy ARP to me?  Or, put another way, if we
didn't have proxy ARP before, how did the ISP do its

Currently I have a publicly routable subnet of
aaa.bbb.ccc.88 - 95. 
.88 is the network address 
.89 is a gateway address that sits at my ISP.  (it is
the other end of my dsl line.
.90 is my m0n0wall WAN IP
.91 - 94 are 1:1 NATted to private space on my DMZ. 
The 1:1 NAT causes the automatic IP aliasing, so that
.91-.94 appear to be on the WAN along with .90.

It all works great.  How does my ISP know to route
like this without proxy ARP already in place?  Will I
need to change this in the pb27 version?


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