John Aldrich wrote:
>
> On Sun, 09 Apr 2000, you wrote:
> > It's a feature, not a critical function. If you use an application that
> > relies on reverse DNS lookups (some IP applications do), then the
> > reverse lookup will fail if your hostname doesn't match the real FQDN.
> > If you have a dialup connection to the internet that causes your
> > hostname to change everytime you call, then you have several choices:
> >
> I repeat my initial question: Name a program which requires
> Reverse Authentication on YOUR side.
Well, I've had this problem with telnet. When hostnames were incorrect,
the telnet connection would hang for some time, then eventually go
through.
Not many people are going to be running telnet services on a dialup, but
I can see it being useful, particularly if somebody cannot afford a
full-time dedicated connection.
> For example, we have a BUNCH of IP addresses that we
> randomly assign to dial-up users. One of them is
> 209.140.61.160, which resolves to:
> "209.1tnt1-160.highertech.net." If I *happened* to be that
> person who got that IP address randomly assigned to me, I
> couldn't be reverse authenticated to a particular machine
> name on my system. For example, my home system is "slave1."
> Try looking up the hostname, "slave1.highertech.net." It
> doesn't exist.
That's right.
Some applications do a reverse DNS, though, and they'll want to see an
accurate hostname (or they'll be hunting in vain for an IP to match the
IP of the incoming packets - hence telnet's hang).
What kppp does with this feature is automatically configure the hostname
based on the FQDN of the IP you are assigned when you dial-in, so that
these reverse DNS lookups work properly.
-Stephen-
