[OpenAFS-devel] IP address change monitoring?

[Jeffrey Hutzelman]

On Saturday, June 23, 2007 10:58:01 AM -0400 Derrick J Brashear 
<shadow@dementia.org> wrote:

> On Mon, 18 Jun 2007, Derrick J Brashear wrote:
>
>> Right now we do this on Windows and MacOS (to trigger updates to the
>> client)
>>
>> What other platforms support a sensible way of getting IP address change
>> notifications? (We could certainly get dhcp notification by script in
>> most  Linuxes but that's OS-specific. I suppose if that's the best we
>> can do I can  provide a helper which you can run when your addresses
>> changed which gathers  and sets new addresses)
>>
>> Thoughts?
>
> Nobody cares? Nobody wants this?

I certainly want this; I carry my laptop around ~everwhere, and it's not 
fun when things stop working or become slow because my machine is 
advertising an address it hasn't had for weeks, on a network on the other 
side of the city.

I haven't looked in much detail, but on Linux it should be possible to get 
this sort of notification directly from the network stack, via a netlink 
socket.  Alternately, most modern distributions are set up to send dbus 
events on interface state changes; this is used by the various GUI network 
management widgets.  Still, this notification is ultimately coming from 
dhclient, so we're probably better off getting what we need directly from 
the kernel if we can (does anyone know if HAL monitors interface state?)

-- Jeff