Hi Folks,
A couple of distinct questions.
1. Computers on a LAN are "behind" an ADSL modem/router
which faces out to the Net.
Seen from outside, this router has IP address
PPP.QQQ.RRR.SSS
From inside the LAN it can be accessed either from
the above address or from an "internal" IP address
192.168.1.1
On the LAN are sundry machines with IP addresses
192.168.1.yyy
or (on a subnet)
192.168.0.zzz
Question: Is there any way by which one can address
one of the "internal" machines from outside (i.e. the Net).
Clearly, for instance,
telnet PPP.QQQ.RRR.SSS
would at best connect to the router (which does respond
to telnet, by the way).
What I'm wondering is if there's anything like
telnet @PPP.QQQ.RRR.SSS!192.168.1.yyy
i.e. to "route" the telnet request for connection to the
internal machine at 192.168.1.yyy through the externally
visible address PPP.QQQ.RRR.SSS
2. This one's a real Linux question!
Suppose the internal machines, instead of having static
IP addresses set up on them, get dynamic IPs handed out
by the router.
With the static IPs, each machine can have a /etc/hosts
file which associates the IP address with the machines
name within the LAN, including a short "nickname". E.g.
192.168.0.6 brandy.my.home.lan brandy br
so, e.g., in the LAN I can do "telnet br".
But, with dynamic IPs, this association would break down.
"brandy" would no longer have IP address 192.168.0.6
So -- What's the equivalent mechanism when dynamic IPs
are used? If I do
telnet br
would this simply not work (because there's no IP/name
association), or is there a mechanism whereby allocation
of a dynamic IP address to brandy.my.home.lan would set
up an association with this name (and to chosen nicknames
"brandy", "br") as in the /etc/hosts file?
And, if so, where does it (and its components) reside?
Thanks, and best wishes to all,
Ted.
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E-Mail: (Ted Harding) <Ted.Harding(a)nessie.mcc.ac.uk>
Fax-to-email: +44 (0)870 094 0861
Date: 11-Jan-06 Time: 17:15:20
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