Stefan Nobis wrote: > > Nathan E Norman <[EMAIL PROTECTED]> writes: > > > Smart people *can* get IPs that haven't been assigned to them, and > > it's a PITA to root them out. PPPoE, while a hack, addresses this > > concern for providers. I wish we used it. > > Tell me more about this. What about configuring the routers only to > route IPs that are assigned on each connection? In the worst case you > set for each connection a static IP. How can anyone use IPs they > haven't been assigned to in this case?
My dear friends, you are totally wrong. But you can learn :-) PPPoE is used, because that way the telco can make sure you must change the IP-adress from time to time and therefore you are stopped from "missusing" your "client-only-line" for "server-use", which would question other products of the telco: german telekom eg. charges around 48 Euro for a flat adsl-rate (768kbit/s down, 128 up) and you must use a dynamic ip-number. a comparable solution also by the german telekom is t-interconnect, 512kBit bidirectional sdsl with a fixed number and costing around 100 Euro for the line and 40 Euro per Gigabyte! You can get as many IP-Numbers as you can explain in a ripe-141-template (dont ask :-). (Yes, this IS totaly, absolutly braindead, but its the truth - and thats the reason why I get bored by the x-files, because after all the big "truth out there" simply is "there are only idiots out there" :-) ah, yes, back to topic: actually chances are good that you can use a nearly fixed ip. Last time I checked t-online, which uses the same radius/ppp-system like t-adsl, you could NACK and SUGGEST IPs while handshaking until you found a number fit for your purpose. Bad: If your ip is already being used, you lost. I dont have t-adsl now, but as I have already worked with dsl at work I know that t-online uses just some dozend lines per router and this router has enough ips for all lines. So I bet a "fried pink cow on white bread" that you can always reserve the last number of the pool. Ok, some hacking in the pppd should do the trick... > Do you want to tell me that for leased lines there is no way to stop > bad people to use IPs that haven't been assigned to them? Where is the > big difference between leased lines and DSL? Actually PPP makes it easier to missuse ip-adresses, because with ppp-over-ethernet you can under some circumstances even allocate several ips at once (which doesnt make much sense). If you give a customer a fixed IP you need only to make sure, that his router-port uses an algorithmus named back-route-verity - then only his official ip may pass. > I'm a beginner in the networking section but even i know some ways to > secure the ISP-side. I can't imagine that all those big ISP like > Worldcom/UUnet have no idea how to secure their IPs. Actually those big guys do not have a clue about technology, but they know to protect their financial assets... Christian Brandt
