[plug] Argh! What have I _done_ ?!

[bob]

A continuing saga of configuring an Alpha for use as a server/gateway.
After much angst Bob thinks that the box is ready for service so puts it
live online. 

Now read on...

Ok, so the network that was working ok is now broken to the point where
I can't ping any of the hosts on the lan. If I down the eth0 i/f on the
server I can see other hosts, however it is unlikely to be a hardware
problem as I've replaced the nic with a known good with no change in
brokenness. Whenever packets are poked at the server all the active
lights flash on the switch (not the case when pinging between hosts )
Its obviously in the config somewhere... but all I did was change the
gateway to point to the new IP# on the lan hosts and delete the default
route to the old gateway on the new one _honest!_ .

I hope someone can point out my stupidity because I'm out of ideas and
about ready to throw it out the window :(. 

I'm not even sure what would be usefull to send at the moment because
everything looks ok AFAIK. but here is a a brief rundown of the old vs
new setups

OLD GW box 192.168.0.1 192.168.0.0/24 network
NEW GW box 192.168.0.50 "" "" 

default route was ...1 now ...50 on lan hosts
default route on GWbox points to fixed IP ppp (same deal as old box) 

ppp works ok (I'm composing this on the GWbox) 

ifconfig on the GWbox shows

eth0      Link encap:Ethernet  HWaddr 00:A0:C9:E1:84:45  
          inet addr:192.168.0.50  Bcast:192.168.0.255 
Mask:255.255.255.0          UP BROADCAST RUNNING MULTICAST  MTU:1500 
Metric:1          RX packets:3493 errors:0 dropped:0 overruns:0 frame:0
          TX packets:3326 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:100 
          RX bytes:254338 (248.3 KiB)  TX bytes:172339 (168.2 KiB)
          Interrupt:16 Base address:0x8000 


ifconfig on the lan hosts shows (typ)

eth0      Link encap:Ethernet  HWaddr 00:A0:C9:A5:F3:A1  
          inet addr:192.168.0.111  Bcast:192.168.0.255 
Mask:255.255.255.0          UP BROADCAST RUNNING MULTICAST  MTU:1500 
Metric:1          RX packets:377 errors:0 dropped:0 overruns:0 frame:0
          TX packets:4045 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:100 
          RX bytes:47192 (46.0 Kb)  TX bytes:203806 (199.0 Kb)
          Interrupt:11 Base address:0xe000 


Kernel IP routing table on the GWbox shows

Destination     Gateway         Genmask         Flags Metric Ref    Use
Iface X.X.X.X    0.0.0.0         255.255.255.255 UH    0      0        0
ppp0 192.168.0.0     0.0.0.0         255.255.255.0   U     0      0     
  0 eth0 0.0.0.0         X.X.X.X    0.0.0.0         UG    0      0      
 0 ppp0

Kernel IP routing table on the lan hosts shows

Destination     Gateway         Genmask         Flags Metric Ref    Use
Iface 192.168.0.0     0.0.0.0         255.255.255.0   U     0      0    
   0 eth0 127.0.0.0       0.0.0.0         255.0.0.0       U     0      0
       0 lo 0.0.0.0         192.168.0.50    0.0.0.0         UG    0     
0        0 eth0


I hope I can get some hints as to how I've borked this one up. 
I had hoped it would be a painless changeover :(. 

Please let me know if you need more info, I'm more than happy to run
whatever  to get this fixed.

Thanks.
-- 
Bob.