WRT54G linksys router

reefa · 03-14-2005, 04:57 PM

I have a WRT54G linksys router connected to a linksys EFAH05W Hub then its connected to an ADSL modem. I have one windows machine connected to the router, and I have one linux box connected to the router, and then I have two laptops connected to it wireless. All these computers have been assigned automatic private DHCP IPs, and they connect to the internet fine, but they all use 1 IP, which is my gateway IP(for some weird reason).
The router is setup to connect with PPPoE. My ISP(SBC) has assigned me 5 sticky IPS over PPPoE.
My problem is I want to beable to use my 5 sticky IPS for vhost in Linux with ifconfig eth0:X but when I do that I can't use those sticky IP's for some reason, I can't ping the ips within my network either.

fr_laz · 03-15-2005, 12:31 PM

Hi,

That's totally normal !
Your WRT54G is doing masquerading (the Linux word) : since most internet users have only one public IP, the routers are made so that they translate all private IPs (192.168.0.0, 172.16.0.0, 10.0.0.0) to the IP they have on their Internet interface. That's a classical routing functionality.

If you configure your 5 public IPs on your LAN machines, they should be able to ping each other if they're connected on the same switch/hub. But assuming your public IPs are 9.1.2.3, 9.1.2.4 and that you also use the private IPs 192.168.0.1, 192.168.0.1 :
9.1.2.3 can ping 9.1.2.4
192.168.0.1 can ping 192.168.0.2
192.168.0.1 canNOT ping 9.1.2.3 : they're not on the same subnet.

Here's the LAN topology you should have :

Code:

PC1 (private dhcp IP)---
                                     |--- Ethernet or wireless WRT54G Internet iface---
PC2 (private dhcp IP)---                                                                              |--- Hub --- modem
                                                                           PC3 (public IP address)---

Every pc connected to your routeur must use private IP (since they're routed !)
Every PC connected to the hub must use a public IP (since they're not routed !)

reefa · 03-16-2005, 04:56 PM

I decided to setup my system like so:

Internet -> Linux(router) -> router(access point) -> LAN. I have 3 computers connected to the LAN, 2 wireless and 2 wired...
And now I can change my IP's in Linux to which ever eth0:X I have.
But all my computers on the LAN IP are directly connected through the gateway IP, lets say i want to change the IP for one of my LAN's to connect through 1.2.3.4 instead of 1.2.3.5 which is the IP all my computers get once they connect to the internet. So I have to do a NAT MASQ, would that solve the problem?