Hi,

I have a box at home that I've installed CentOS 5 on to. I'm new to Linux, so before connecting it up to the router I wanted to try and understand the network settings, so I connected it directly to my other PC with an RJ45 cable.

From Windows 7 I can ping all known static IP addresses, but from Linux I can only ping the Linux addresses, not the Windows 7 one.

Below are the TCP/IP IPv4 settings, all IPv6 settings are set to auto-assign.

Windows box (uses wireless connection for the router):
Local Ethernet Adapter
IP Address: 30.10.0.1
Subnet: 255.255.0.0
No gateway, primary/secondary DNS.

Linux box:
Three adapters:
Two onboard LAN, both configured to:
IP Address: 30.10.0.2 / 30.10.0.3
Subnet: 255.255.0.0
Gateway: 30.10.0.1
No primary/secondary DNS.

One LinkSys PCI card:
IP Address: 20.10.0.1
Subnet: 255.255.255.0
Gateway: 192.168.1.1 (my router)
Primary/Secondary DNS: my ISPs details.

The idea was to connect the box directly to the router (with RJ45) and to be able to remote login from my main PC to this one. This box is to be my home server, which I was going to put virtual machines on to for things like my development work and such.

Any help is much appreciated, since this is a learning experience for me.

Regards,
Rob.

If this is a home environment, and you have a router connecting to your ISP, then the first thing I see is your IP addressing does not make any sense. Sorry to put it that way, but it does not.

Please have a read through this link. --> http://tldp.org/LDP/nag2/x-087-2-iss...addresses.html

Take special note of the the Private IP addresses for Class A, B and C. Any other IP address you should not be using, unless you keep the network completely private, ie no outside connection to the internet.

Home routers do a function called NAT. ( Network Address Translation ). Your side, in your home should use a class A, B or C private address. The side of the router that connect to your ISP will have an IP address controlled by your ISP. NAT on transmit will change the private IP address to the one on the ISP side. On Receive, the process is reversed. All the systems on your side can belong to the same, or different sub-nets, that is your choice.

Look at the doc for your router. It will tell you what IP address rages it will support. A lot of home routers use 192.168.x.y addresses.

If all the systems are in the same sub-net, then you will be able to ping to each one from the other.

Beyond that, I'm not sure what any problems you have are. Post back after you have a look at the link any problems...