James Cameron writes: > I've heard and seen that Windows systems show point to point links as if > they are Ethernet adaptors ... and I shake my head in confusion. Linux > point to point links are different: the remote IP address has no use, > and I find everything works fine without it. I mostly agree with your rant; for the typical "simple" end-user connection to an ISP, the remote address is not terribly necessary or interesting. But it's not quite accurate that a remote address "has no use." The first observation is that if you have a PPP link running IP, then the termination point must (by definition) support IP. Devices that support IP but refuse to reveal an address are fairly boring, because you usually can't talk directly to them, and they can't be managed. Rather than being deliberately ornery, those devices ought to reveal that address. One obvious use of a remote address is in just testing the link at the IP level. If you have a remote address on the link, then you can ping the peer and isolate IP-level link problems versus routing-related problems. If you don't have a usable remote address on the link, then you can't necessarily directly ping the peer (even though it obviously is an IP node), and anything you do contact will be at least one extra hop away -- meaning that isolating problems is a bit harder. Another use is in routing. If you run a routing protocol, then the source address on each peer's message will be local link's IP address, and any unicast messages demanded by the protocol (e.g., running BGP) will typically be to the remote address on the link. Still another is in link monitoring. Some peers will allow you to do simple SNMP queries to retrieve link statistics from the remote end, which can be extremely useful in diagnosing network faults and tracking usage. So, while the address isn't all that interesting to some classes of users, I would maintain that any IPCP deployment that refuses to reveal at least some address for itself is very poorly done indeed, reflects a lack of basic networking clue on the part of the operator, and ought to be repaired or replaced. -- James Carlson 42.703N 71.076W <carlsonj@xxxxxxxxxxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe linux-ppp" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
