Hi

I have a Gentoo Linux box hosting several virtual machines (VMs) with Xen which I want to be available from the internet via their own public IP.

With my old ISP, I used to simply make IP aliases and then add SNAT rules between the public IP aliases and the local IPs of my VMs (using shorewall). Since I started feeling bad about "stealing" IPs from my ISP I have recently changed ISP. My new ISP allows me to buy up to 5 public IP addresses. The problem is that these IPs has to be requested from their DHCP server and they assign IPs based on MAC addresses (Each MAC gets one, and only one IP). This gives me a problem since I cant simply create IP aliases anymore given that aliased interfaces inherits their MAC address form the physical interface.

I have tried creating multiple dummy and TUN/TAP interfaces and bridging them together with the physical interface hoping that they would be able to request an IP from my ISP's DHCP server. But all these attempts have been unsuccessful and not even the physical interface seems to be able to request an IP when being bridged.

So, to summarize: I need a way to request multiple IPs from a DHCP server through one physical interface while making it appear to the DHCP server as if I was requesting the IPs from different NICs with different MAC addresses. Does anyone have any ideas about how I can make this work?

Please ask if you need any more information.

Thanks in advance
Truls Asheim

I am also interested in obtaining 2 public IPs via dhcp on one NIC. The reason is that if Shaw ISP detects p2p traffic it puts a cap on your IP which in turn cripples ssh, rsync, sftp, freenx etc. If I download OpenOffice.org or knoppix using torrent technology - I get a cap on my bandwidth. It becomes painfully slow to type on a remote computer over ssh - even with p2p turned off. The only way to fix it is to change my MAC, reboot my modem and issue a dhcp request for a new IP - this only lasts until I startup a p2p program again.

Shaw allows for 2 IPs so it would be nice to do the following:

1st IP) dedicated for regular web browsing ssh, sftp, rsync, freenx.

2nd IP) dedicated for p2p traffic.

I'm not sure how to create two virtual MACs that share one physical NIC - this is needed to dhcp-request two separate IPs.