IP/IP and IPv6/IP tunnels and dynamic IP address

[Urs Thuermann <urs@isnogud.escape.de>]

My ISP provides a single, dynamic IPv4 address to me.  I have
configured several tunnels, IPv4 in IPv4 and IPv6 in IPv4, to several
sites.  This is running on a very old Linux installation and I want to
move that to a Debian system.

I know how to set up /etc/network/interfaces for such tunnels if the
IPv4 address is static.  However, with dynamic IPv4 address you do not
only needed ifup <tunnel> and ifdown <tunnel> but also a way to update
the remote tunnel configuration when the local IPv4 address changes.
E.g. for Hurricane Electric tunnel broker you access a certain URL
(using e.g. wget) where the URL encodes your current IPv4 address.  At
another site I need to execute a command using ssh.

I know how I can do that using cron and/or pppd configs.  But I'd like
to know if Debian has some standard way to update tunnel configs,
preferrably in /etc/network/interfaces with the rest of the interface
definition.

urs