Network Topology help

Message

casso · Post by **casso** » Mon Oct 16, 2006 11:53 pm

Hi,
I am not sure whether I need a bridge, advanced IP routing or what else I may need for this network setup. There are two scenarios, so please read both

I have a server that has only one ethernet socket and no available PCI slots or USB to allow for wireless. My gateway is not my main server. It has a static IP address while all others have a dynamic IP. I have a wireless PCI card in my gateway. The gateway has three interfaces, one ethernet for the network, one PPP for dial-up and one wireless.
All I want to do is get the wireless card and the computer connecting via it to access each and every computer on the network, get an IP and be able to access the internet. I have extensive firewall rules and I would like not to duplicate them for both of the interfaces. In other words, I don't want to have identical rules and tables for two seperate interfaces if I can avoid them. I know that using a bridge can solve this, but I don't know if a bridge can give the connecting computer an IP address from the main server, or allow that computer perfect access to every other computer over the network.

I also have a computer that I will set up with Xen very soon. Xen is a hypervisor (think virtual machine for now). This means I will have several TAP interfaces running on it and I want each interface to be able to talk to each other and access the network. Just as above, these interfaces should get an IP from my main server. I do not wish to use NAT so that each computer can access the network from the ethernet device Xen is running on (a non-TAP device). It is essential all computers have a dynamic IP from the range for the network.

Maybe this is one of those really easy things or maybe it is actually quite difficult, I don't know. All I know is that I know little about bridges and might just know enough about routing to get me by, but that is all.

Thanks for your time,
Michael Cassaniti

casso · Post by **casso** » Tue Oct 31, 2006 2:52 am

Wow! Plenty of views yet not one reply. I know I'm marked as noob in these forums, but I do know a bit.

All I want to know is if I am going to get two network interfaces on a computer to be able to talk to each other, meaning they pass traffic from one interface to any device connected to the other interface, what setup would I need. I need more than just IP traffic, I also need to get an IP (via DHCP) through this mechanism.

Anyone want more clarity, just let me know. Can someone at least give some suggestion or give an example of their setup for some background info ... Can anyone point me to a good document about network bridging as well.

Thanks,
Michael Cassaniti

GJtje · Post by **GJtje** » Thu Nov 02, 2006 8:57 pm

So basicly you just want the gateway to be an access point. There should be plenty of tutorials for that.

For Xen I don't really see what your question is. You just need DHCP or assign ip's to the guests manually. The Xen script automatically creates bridges for the virtual nic's of the Xen guests.

casso · Post by **casso** » Fri Nov 03, 2006 4:35 am

Ignore the part about the wireless connection for now. The problem is not wireless related, it's related to IP and ARP traffic.

My question is, would a bridge be sufficient? I want to be able to send and receive traffic from one nic to another nic, regardless of the type of nic or whether it has 1 or 100 computers "viewable" from the other end. I have had some trouble with bridges in the past, this is why I am unsure. I want too be sure that all my nic's can get an IP from the DHCP server connected through one interface and still be able to talk to any other nic. Maybe I should ask what a bridge is actually supposed to do and see if that fits the profile.

Have I asked the right question, or am I still too fuzzy?