IP forwarding in SuSe 8.0

[Roger Hayter]

I wonder if anyone has any ideas what might be going wrong here?  I have 
a Suse 8.0 machine which I plan to use as a router/firewall.  Using 
routeable IPs. It has 3 NICs, one of which gets its address by dhcpcd 
(eth0).  This is for technical adsl modem reasons, but it is always the 
same address.  IP forwarding works between the two NICs (on different 
subnets) which have preset IPs (eth1 and eth2), and to the actual IP 
address of eth0.  Routing is set up so I can contact the wider Internet 
from the firewall machine itself, via eth0, and both incoming and 
outgoing connections work fine.  (Not left on long in this un-firewalled 
config, in case anyone out there is listening!) But the kernel will not 
accept any packets coming in from eth0 which should go to eth[1 or 2] or 
vice versa.  It isn't the cards themselves, as I have swapped their 
roles.  Is this a limitation of dhcp, or can anyone suggest another 
theory?  I am tempted to try a) Suse 7.3 or b) dhclient instead of 
dhcpcd, but either would be very laborious.
-- 
Roger Hayter