arplookup 192.168.0.1 failed: host is not on local network confusion

[lists at chrishowells.co.uk]

Hi,

In my server, I have three ethernet cards: xl0, xl1 and vx0. xl0 and xl1
are bridged and one of them is connected to my ethernet switch, the other
to my wireless acess point. xl0 has an IP address of 192.168.1.1.

vx0 is connected to my ADSL modem. My ADSL modem (D-Link ADSL 300G+)
insists on using an IP address of 192.168.1.0, but via DHCP it hands vx0
one of the IP addresses in the /29 that I have from my ADSL provider.

In dmesg I often see: arplookup 192.168.0.1 failed: host is not on local
network

Now obviously 192.168.0.1 isn't on the same network as xl0's 192.168.1.1
since xl0 has a netmask of 0xfffff00.

But what is causing this message? Something I read suggested dhcpd, which
I have handing out IP addresses on 192.168.1.0/24, but I don't see why.

I am aware that this has been discussed before, but I can't see anything
misconfigured, and while this is only a minor annoyance I would quite like
to get it fixed.

ifconfig looks like this:

xl0: flags=8943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST> mtu 1500
        options=3<rxcsum,txcsum>
        inet6 fe80::201:2ff:fe9b:c86%xl0 prefixlen 64 scopeid 0x1
        inet 192.168.1.1 netmask 0xffffff00 broadcast 192.168.1.255
        ether 00:01:02:9b:0c:86
        media: Ethernet autoselect (100baseTX <full-duplex>)
        status: active
vx0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
        inet6 fe80::260:97ff:fe90:4ad7%vx0 prefixlen 64 scopeid 0x2
        inet 82.68.135.38 netmask 0xffffff00 broadcast 82.68.135.255
        ether 00:60:97:90:4a:d7
xl1: flags=8943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST> mtu 1500
        options=3<rxcsum,txcsum>
        inet6 fe80::201:2ff:feb8:3c56%xl1 prefixlen 64 scopeid 0x3
        ether 00:01:02:b8:3c:56
        media: Ethernet autoselect (none)
        status: no carrier

Thanks for any help
Chris Howells