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Re: Dhcp and ssh

On Sat, Dec 06, 2003 at 11:55:29AM -0700, Monique Y. Herman wrote

> I'm pretty sure ssh still gets upset if a hostname doesn't match the
> expected IP .... known_hosts records both the hostname and the IP,
> then gets upset if either changes in relation to the other.

  ??? I'm on an ADSL ISP, and I have a dynamic IP address to the outside
world.  For even ,ore fun, I'm behind two layers of NAT.  Yet I still
manage to ssh in daily to a remote machine to collect my email
(including this list).  Here's my setup...

   Dynamic publicly
   routable IP address
 v<assigned by my ISP    v<external address
 v                       v
 v  ____________         v __________________ 
 v |            |        v|                  |
 =<  ADSL modem  >=======<  Netgear Router   |
   |____________|^        | Internal address |
                 ^        |   |    ^        |  | ^        |_  ___  ___  ___  |
internal address>^          ||   ||   ||   ||
                            ||   ||
                            ||   ||
         ___________________||   ||
        |                     |  ||
        | Linux |  ||
        | mask|  ||
        |_____________________|  ||
             |                     |
             | Linux |
             | mask|

  The ADSL modem has internal address mask
I could get away with netmask  I set the router's
"external/WAN" address as netmask (netmask would also work here.)  I also set the router's external
default gateway route to (i.e. the modem's internal address).

  Apparently, the primary rule with double-NATting is not to overlap IP
address ranges.  So I decided to select the block defined by netmask (same as  The
allocations I use are... base address (not supposed to have a machine here) \  \ are for up to 4 machines to hook  / up to the 4 ports on the router / I haven't quite figured out a use for this address The internal (LAN side) address used by the router.
                This follows the default convention for router address. The broadcast address used by the router (syslog output).
                This follows the default convention for broadcast address.

Walter Dnes <waltdnes@waltdnes.org>
I'm not repeating myself; I'm an X Window user, I'm an ex-Windows user

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