vhost with proper reverse DNS on an ADSL2 connection won't bind
 

I'm working on an ADSL2 connection that connects via PPPoE and it is assigned a static IP. On top of the static, the ISP has assigned a small block of 6 useable IP addresses.

- The primary static IP is on the interface ppp0
- The other 6 IPs are configured as eth0:1, eth0:2, eth0:3 etc.

With the above setup all IPs are reachable and useable on the internet.

- The revers DNS has been updated for a few of these and resolves with no problems. ie: eth0:1 has the 123.123.123.123 IP and resolves to blah.host.com and blah.host.com resolves to the IP address.

- To test this I have tried a program like BNC to bind to the IP address on eth0:1 but for some reason when connecting externally the host address is coming up with the FQDN on ppp0 interface IP, not the vhost IP.

Questions is, is this the normal behaviour since its a PPPoE connection and would only work if the ISP supported a bridged connection? something on the ISP end not allowing this to work?

Thanks.

AFAIK when you have a small block of addresses normally you would have to route them locally for the block. If you had six usable that would suggest an 8 block and it would typically be assigned like this:

I think it's usual for all external requests for addresses in the block to be sent to the 'router' address (usually the highest in the block before the broadcast address) - however I would not swear that to be the case in every scenario and I'm sure one of the networking experts here may have other examples / caveats to this?