I have a home network with 3 subnets (I like to play around!)
I've been struggling with something that I thought would be easy, but after a few days I'm no closer to the answer. My network is depicted in this image
The main subnet is 192.168.1.0/24, which is connected to the 192.168.2.0/24 subnet via a laptop with an ethernet (192.168.1.2) and wifi (192.168.2.1) adapter.
I am running hostapd and dhcpd on the laptop with the 2 NIC's (with IP Maquearading) - so I am using it as a WiFi hotspot. The setup there is working fine (has been for some time). I recently added a wifi router, which is connected to the 192.168.1.0/24 subnet via a WAN connector ethernet link (192.168.1.10), dishing out DHCP addresses in the 192.168.3.0/24 subnet range.
The main subnet is connected to a Linux box (192.168.1.1) which acts as a gateway router to the internet for the internal network (with IP Masquerading for packets to and from the public internet).
If I am on the Linux box (router) I can ping 192.168.1.2 as well as 192.168.2.2 (after adding the entries in the routing table to reach the 192.168.2.0/24 subnet):
ip route add 192.168.2.0/24 via 192.168.1.2
My goal is to reach the mobile phone (192.168.2.2) from the laptop (192.168.3.2) connected wirelessly to the wifi router, which in turn is connected to the 192.168.1.0/24 subnet.
This is where things go wrong. I thought that the packets originating from 192.168.3.2 - which are destined for 192.168.2.2 - will be sent to 192.168.1.1 (the default gateway for the wireless router), and since 192.168.1.1 can ping 192.168.2.2, I assumed that this would work (because of the routing entry mentioned above).
IP Forwarding is enabled on the Linux router (192.168.1.1) as well as on the laptop acting as a WiFi hotspot. Is what I am trying to do here possible, or am I missing some fundamental concept?
- Routing tables
Routing table for 192.168.1.1: Destination Gateway Genmask Flags Metric Ref Use Iface 0.0.0.0 10.0.0.1 0.0.0.0 UG 10 0 0 eth0 10.0.0.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0 192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 eth1 192.168.2.0 192.168.1.25 255.255.255.0 UG 0 0 0 eth1 Routing table for 192.168.1.2: Destination Gateway Genmask Flags Metric Ref Use Iface 0.0.0.0 192.168.1.1 0.0.0.0 UG 0 0 0 eth0 192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0 192.168.2.0 0.0.0.0 255.255.255.0 U 0 0 0 wlan0
Thank you all!