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.
or if you have a capable adsl router, you can nat all four addresses to
internal server addresses
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?
this seems like a wierd setup... so for each /30 customer they would
set up one of the four ip addresses on the interface of their provider router?
I don't know about current practice, but older vtx (ex-tiscali, to be precise),
the practice was to get an unrelated ip on the wan interface.