From: Stephen Hemminger <redacted>
Date: Thu, 1 Mar 2007 17:30:30 -0800

What about implementing the unused arp_announce flag on the inetdevice?
Something like the following.  Totally untested...

Looks like it either was there (and got removed) or was planned but
never implemented.

This idea is fine.  But:

+	case NETDEV_CHANGEADDR:
+		/* Send gratuitous ARP in case of address change or new device */
+		if (IN_DEV_ARP_ANNOUNCE(in_dev))
+			arp_send(ARPOP_REQUEST, ETH_P_ARP,
+				 in_dev->ifa_list->ifa_address, dev,
+				 in_dev->ifa_list->ifa_address, NULL, 
+				 dev->dev_addr, NULL);

We'll need to make sure the appropriate 'arp_anounce' address
selection is employed here.

One idea is to change arp_solicit() such that it can be invoked in
this context, or provide a new helper function which will do the
source address selection rules of 'arp_announce' and then invoke
arp_send() as appropriate for us.