It seems that vtx has some very strange way of configuring the /30 subnet when customers order 4 fix IP addresses.
Normally when someone orders a /30, the ADSL router's PPP interface would get an address from an unrelated address range. The 4 addresses from the customer's /30 subnet can be used by the custumer for the network and broadcast addresses (-2), the router's LAN interface (-1), leaving one address for a server or desktop machine.
However, this seems not to be the case at vtx.ch. As two vtx engineers explained to a (tech-savvy dipl. Inform.) customer, they use the addresses from the /30 subnet for the PPP link between their last router and the customer's ADSL router. So in effect, this means ordering a /30 subnet (the 4 fix IP addresses option) from vtx gets you the same as ordering a single fix IP address -- you get a static address on your ADSL router's PPPoA/PPPoE interface, period. To actually use the static address on a server/desktop, you need to either configure destination NAT on your router or operate it in bridging mode and run PPPoE directly from the server/desktop.
Can anybody confirm that this is current practice at vtx? Are other providers doing the same?
-Dan