[Sheflug] Network design problem

[Peter Humphrey <peter@xxxxxxxxxxxxxxxxxx>]

I hope there's an IP guru out there who can help me with this.

My home network seems to be getting more complex all the time. The bit I'm 
having a problem with is the wireless LAN, namely that my wife's laptop 
cannot make a connection to the outside world. This is the topology:

ISP <-- ADSL modem <-- Gateway <-- Ethernet switch.

Also connected to the switch are my workstation and a miscellaneous server. 
The other side of the server has a wireless access point for the laptops.

I've defined an overall prhnet as 192.168.0.0/16, with the ethernet as 
192.168.128.0/17 and the wireless net as 192.168.192.0/19. (The gateway's 
external net is 192.168.0.0/19, and the box has a third interface, dmznet, 
on 192.168.64.0/19, and the server has a virtual net used by VMware on 
192.168.224.0/19, but I hope they don't contribute to my problem.) Thus, 
the ethernet is a subnet of prhnet; the other nets are subnets of the 
ethernet, masked on the top two bits of the third byte.

On the server (all boxes are running Gentoo):

$ cat /etc/networks
loopback        127.0.0.0
prhnet          192.168.0.0/16
outnet          192.168.0.0/19
dmznet          192.168.64.0/19
ethnet          192.168.128.0/17
wapnet          192.168.192.0/19
vrtnet          192.168.224.0/19

$ cat /etc/conf.d/net
config_eth0=( "192.168.128.49 netmask 255.255.128.0 brd 192.168.255.255" )
routes_eth0=( "default gw 192.168.128.1" )
config_eth1=( "192.168.192.210 netmask 255.255.224.0 brd 192.168.223.255" )

It seems to me that the wireless subnet (wapnet) should be routable through 
the ethernet (ethnet), but watching the server's interfaces with tcpdump I 
see pop3 requests from the laptop coming in on the wireless interface but 
not going out on the ethernet. I do have ip_forward set to 1, and:

$ sudo iptables -L
Chain INPUT (policy ACCEPT)
target     prot opt source               destination

Chain FORWARD (policy ACCEPT)
target     prot opt source               destination

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination

I looks as though I've made a mistake in the topology, but where?

-- 
Rgds
Peter

_______________________________________________
        Sheffield Linux User's Group
  http://www.sheflug.org.uk/mailfaq.html
 GNU - The choice of a complete generation