> As far as upstream routers are concerned, it makes no difference to
> them at all. The result is the same in both cases: m0n0wall responds
> to ARP queries for a given IP address and therefore receives packets
> destined to that address and can then determine their fate. I don't
> know what went wrong with proxy ARP in your case, but (assuming it
> was set up properly and no old ARP information was cached) it would
> have been no different with IP aliasing on the WAN interface.
> Besides, proxy ARP isn't something that your ISP has to enable - they
> don't even need to know that you're using it, because in fact their
> router won't even be able to tell whether you use aliasing or proxy
> ARP (as far as MAC address resolution is concerned).
I am not network guru and just know that when I complained about the
situation they responded that they hadn't enabled arp proxying in their
Cisco router. And now it works.
But I still think that it had something to do with "proxy arp" vs. "real
ip" as the old "real ip"-firewall didn't have problems like this. I am not
blaming M0n0wall though, nor my ISP. They just in this case repelled each