[TriLUG] DDNS (and maybe DHCP) on host not router

[Tom Roche]

Tom Roche Fri, Jan 04, 2008 at 01:14:04PM -0500 (rearranged)
 >> in that PN

i.e.
                                    lane
                                   /
  Roadrunner -- Surfboard -- DI-604 -- laptop
                                   \
                                    backend

 >> only the DI-604 is getting an IP#: it's firewalling, DHCPing,
 >> port-forwarding. So putting a dyndns client on one of lane or
 >> backend could not work, correct? Or am I missing something?

Brian McCullough Fri Jan 4 13:18:28 EST 2008
 > No, actually it doesn't matter _where_ the client is. DynDNS records
 > the "public" point where the client is talking to the network, not
 > its internal address. [Wherever] RR gives you your IP address (
 > whether the modem, the router, the firewall ) is the point that
 > DynDNS is concerned with,

Right, but in the PN above, it *is* the router that's getting the IP#,
so it's the router which needs its DNS record updated when its IP#
changes, so it's the router that needs the dyndns update client ...
no? (At least, that's how I understand RR's Surfboards to work--they
give 1 IP# to 1 attached device, and if you change the device you've
gotta powercycle the modem.) And won't that be the case whenever the
router is firewalling?

TIA, Tom Roche <Tom_Roche at pobox.com>