Any idea why this might happen on a 1.5.2 machine?

|mamers[~] 2>: ifconfig ex0
|ex0: flags=8863<UP,BROADCAST,NOTRAILERS,RUNNING,SIMPLEX,MULTICAST> mtu 1500
|        address: 00:01:02:9a:59:35
|        media: Ethernet autoselect (100baseTX full-duplex)
|        status: active
|        inet 10.0.109.1 netmask 0xff000000 broadcast 10.255.255.255
|        inet alias 10.0.1.1 netmask 0xff000000 broadcast 10.255.255.255
|        inet alias 192.168.110.2 netmask 0xffffff00 broadcast 192.168.110.255
|        inet6 fe80::201:2ff:fe9a:5935%ex0 prefixlen 64 scopeid 0x1
|mamers[~] 3>: ping 10.0.109.1
|PING 10.0.109.1 (10.0.109.1): 56 data bytes
|64 bytes from 10.0.109.1: icmp_seq=0 ttl=255 time=0.063 ms
|64 bytes from 10.0.109.1: icmp_seq=1 ttl=255 time=0.082 ms
|^C
|----10.0.109.1 PING Statistics----
|2 packets transmitted, 2 packets received, 0.0% packet loss
|round-trip min/avg/max/stddev = 0.063/0.072/0.082/0.013 ms
|mamers[~] 4>: ping 10.0.1.1
|PING 10.0.1.1 (10.0.1.1): 56 data bytes
|ping: sendto: Host is down
|ping: sendto: Host is down
|^C
|----10.0.1.1 PING Statistics----
|2 packets transmitted, 0 packets received, 100.0% packet loss
|mamers[~] 5>: ping 192.168.110.2
|PING 192.168.110.2 (192.168.110.2): 56 data bytes
|ping: sendto: Host is down
|ping: sendto: Host is down
|^C

I suspect a routing issue, however other machines on my network can ping
all of these addresses (and log in via them), so the machine obviously
knows something about those addresses but not when it initiates anything

what is even more weird is that when I ping the aliases as above, I can
see this machine ARPing on the local network segment via ex0 for its own 
aliases!

as far as I know I'm not doing anything funky with the tcp/ip stack - I'm
not filtering anything and I don't have any extra routing setup going on

I have a laptop that is configured pretty much the same which is able to
ping its own alias interfaces fine ...

I'm not sure where to go next to solve this ... does anyone have any
ideas?

-- 
Malcolm Herbert                                This brain intentionally
mjch@mjch.net                                                left blank