One LAN router (192.168.1.1) gives an static DHCP address and Internet connection to a WiFi router (192.168.10.1), which in its turn is the DHCP server of its wireless network.

I can ping the WiFi router from one computer connected to it, but I can't login the the other one. I can the WiFi routers' admin web page, but I can't connect to Internet.

The funny thing is that exactly the same routers' config and computer works across the wireless and wired networks, both pinging and browsing internal and external web pages when booting the computer in Windows XP.

The iptables of the computer are accepting all. dhclient-scripts generates the nameserver 192.168.1.1 at the client's /etc/resolv.conf. The client has inet addr:192.168.10.100. Bcast: 192.168.10.255 and Mask: 255.255.255.0 address.

The command grep -inr '192.168.1.1' /var/log/* doesn't bring up anything.

I don't know what else to check.

What is the IP/mask of your LAN router. I assume it's 192.168.1.1/255.255.255.0 .
This means that everything on your first LAN must have an IP in the range
192.168.1.[0...255], including the WAN port of the second (WiFI) router.

I assume you have your WiFi router's WAN port connected to your LAN router.
This means the LAN router should assign the WifiRouter's *WAN* port an IP in the
range 192.168.1.[2...255] . Otherwise the WiFI router cannot communicate with
the LAN router.

You can choose to have he WiFi router dhcp serve any address range you like for
th subnet (except for 192.168.1.x). So 192.168.10.x is perfectly fine for your
second wireless LAN.

If you examine the WiFi router admin pages you will see the IP/mask assigned
to the WAN of the WiFi router, and I suspect it does not match your first lan
(192.168.1.x).

Yes, thank you. I flashed the WiFi router and checked the masks. Now the computer 192.168.10.100 pings and browses other web servers of computers connected to the LAN router, like 192.168.1.100.

Computer
IP Address 192.168.1.100
|
LAN router
IP Address 192.168.1.1
Subnet Mask 255.255.255.0
|
IP Address 192.168.1.103
WAN router
IP Address 192.168.10.1
Subnet Mask 255.255.255.0
|
Computer
IP Address 192.168.10.100

The computer 192.168.1.100 doesn't ping '192.168.10.1' or '192.168.10.100'. When 192.168.10.100 tries to ssh 192.168.1.100, the later logs the event as coming from '192.168.1.103'. '192.168.1.103' is the address given by the LAN router to the WiFi Router. The computer 192.168.1.100 doesn't ping 192.168.1.103 either!

How can 192.168.1.100 ping 192.168.10.100?

Thanks.

After some research I ended up turning the WiFi router into an access point: I allocated a static 192.168.1.X ip address to it, disabled its dhcp routing and connected of of its lan ports, instead of the wan one, to one of the lan ports of the main router.
Everything is 192.168.1.X now.