Is there any way to get an async notification (perhaps through something like a Linux message queue or Unix socket) when a DHCP client is either unable to renew its lease, or the address obtained changes from the previous value? I've got the ISC client and will dig into it to determine if it supports such a feature, but thought I'd ask here in parallel. (I'm trying to find out if there are any DHCP clients out there which already support this capability.)

If you're curious: We have an application where we're doing auto-registration of an IP camera to an external server. If the camera's dynamically assigned address changes, we need to restart the auto-reg state machine. I've seen implementations where a socket is opened and a SIOCGIFADDR ioctl used to fetch the IP addr, but I'd sure like to avoid polling like this if possible.

depends what client you use but this is presumably exactly what you want. http://linuxreviews.org/man/dhclient-script/

1 members found this post helpful.