Home network setup help, 2 routers 3 PCs

Message

Malcolm · Post by **Malcolm** » Tue Sep 21, 2004 2:39 pm

This is what I'd like to do, but have little idea how to do it.

Currently I have 2 PCs and 1 LCD dead laptop. I'm running the laptop as a Gentoo server, one PC is the family PC (Windows) and the other is my Gentoo/Windows workstation.

What I'd like to do is have a normal Ethernet connection between the family PC (Windows based) and the router, a wireless connection between my wireless router and the laptop, and have my workstation connected to the laptops NIC card (I still need to buy a cross-over cable).

The wireless router controls the PPPoE connection.

Any ideas how I can do this? Because my description above is kinda crappy heres a diagram:

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|--------------|
| DSL Modem    |
|--------------|
       | (RJ-45)
|-----------------|
| Wireless router |
|-----------------|
     |        |
     |         \
     | (RJ-45)  \ (802.11b)
|----------|    |---------------|
| Ethernet |    | Laptop Server |
| PC (NIC) |    | (wireless)    |
|----------|    |---------------|
                       | (RJ-45)
                |------------------|
                | Ethernet PC (NIC)|
                |------------------|

So the laptop would be running a dhcp server and routing, as well as forwarding(?).

I did something like this 2 or 3 years ago in college with Zebra but I dumped the notes, I wouldn't mind some direction

marvin · Post by **marvin** » Thu Sep 23, 2004 9:55 am

I would just give the PC behind the laptop a static ip (e.g. 192.168.0.17), because I think it will be easier to setup routing that way.
Set the laptop as gateway on the PC behind it. Then your /etc/conf.d/net (on the laptop) can look like this:

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# to ethernet pc
iface_eth0="192.168.0.16 broadcast 192.168.0.255 netmask 255.255.255.254"
# wlan
iface_eth1="192.168.0.2 broadcast 192.168.0.255 netmask 255.255.255.0"

# For setting the default gateway
gateway="eth1/192.168.0.1"

This should make a subnet of 2 ips inside the local subnet for the ethernet PC and the laptop and set up correct routing.
Then enable forwarding by adding:

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echo "1" > /proc/sys/net/ipv4/conf/all/forwarding

to /etc/conf.d/local.start

This is a bit of a hack and might only work if the entries in the routing table appear in the correct order:

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# route -n
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
192.168.0.16     0.0.0.0         255.255.255.254   U     0      0        0 eth0
192.168.0.0     0.0.0.0         255.255.255.0   U     0      0        0 eth1
127.0.0.0       127.0.0.1       255.0.0.0       UG    0      0        0 lo
0.0.0.0         192.168.0.1    0.0.0.0         UG    0      0        0 eth1

If this doesn't work you might give the the ethernet PC and ethernet card of your laptop just another subnet (192.168.1.x). But that may cause problems if your wireless router supports only one subnet. Then you have to make NAT on your laptop such that the wireless router sees only ips from 192.168.0.x.

In all cases dhcp should also work if you set the right ip range.

Malcolm · Post by **Malcolm** » Mon Sep 27, 2004 2:37 am

I've almost got everything going alright, I'm just having problems getting both PCs to talk to each other.

Dsl modem is connected to my hardware router via the uplink port.

My router has a static ip of 192.168.2.1 and is running a dhcp service.

The family PC is connected to the routers #1 port, with 192.168.2.100.

My laptop has a wireless connection with a static IP set to 192.168.2.120.

My laptop is running dhcpd, iptables with forwarding and dnsmasq.

My laptop has a static IP of 192.168.0.1 on the ethernet port.

My dual boot system is connected to the laptops ethernet port and browsing the web fine, usually assigned the address 192.168.0.105.

How can i get both PCs to talk to each other? Its not really nessessary but it would help me out quite a bit.

thanks for any help

servermonk · Post by **servermonk** » Mon Sep 27, 2004 2:52 am

That depends on what you mena by "talk to eachother". Are they unreachable from their respective networks? You could try changing the netmask so they're on the same 'network'.

Malcolm · Post by **Malcolm** » Tue Sep 28, 2004 2:12 am

servermonk wrote:That depends on what you mena by "talk to eachother". Are they unreachable from their respective networks? You could try changing the netmask so they're on the same 'network'.

talk to eachother as in nfs/samba shares

I'll try adjusting the addresses so they overlap, but I thought that would break something...

Malcolm · Post by **Malcolm** » Sat Oct 02, 2004 10:37 pm

Everything's up n' running, thanks