On 09/01/2018 04:20 PM, Peter Jeremy wrote:
My approach is a script on the client system (that has
that compares its external address with its address in DNS. If they
differ, it sends an update to the DNS server. The script is hooked into
dhclient so it's invoked when the address is updated or renewed.
That sounds like a very reasonable method to manage Dynamic DNS for a
That's not quite what I was thinking of. ;-)
First: I'm assuming that the VPS in question has two public IP
addresses. (It may be possible to do this with one, but the routing
gets quite a bit more complex.)
Second: Establish a VPN / tunnel between a client machine and the VPS.
Third: Enable Proxy ARP on the VPS for the second (unused & unbound to
the VPS) IP.
Fourth: Add a route to said second (unused & unbound to the VPS) via
the far side of the VPN / tunnel.
Fifth: Bind the second (unused & unbound to the VPS) ip on the local
VPN / tunnel client.
Hypothetically this will get the second (unused & unbound to the VPS)
such that it can be bound and used by a local client. Thus the local
client will have the globally routed IP address extended to it from the VPS.
The "DNS server" is a hack I've added
to Iodine - for an "A" lookup,
it does a readlink(2) of the FQDN in a config directory and treats the
target as an IPv4 address. This FQDN is within a subdomain I've
delegated to Iodine - I have a CNAME pointing into the subdomain. The
client updates the symlink by SSHing to the DNS server host and running
a command that takes the domain name and address and updates the symlink.
Intriguing. I'll have to check out Iodine. Thank you for the information.
Whilst I've managed to get a static address at
home, I still find it
useful for VPSs where the address is static whilst the instance is
running but not preserved across rebuilds.
As an example, lookup gce1.rulingia.com
 This is good enough because Australian ISPs don't believe in IPv6
I'll have to check out what you're suggesting.
Grant. . . .
unix || die