Re: Generating Unsolicited Neighbor Advertisements

[Edgar Fuß <ef%math.uni-bonn.de@localhost>]

I'm confused.

In the IPv4 world, adding an address to an interface causes an Gratuitous ARP 
to be sent, informing the world about the new MAC

In the IPv6 world, there are Unsolicited Neighbor Advertisements, but they are 
declared optional (speeding up things) and NetBSD seems not to send them.

Now my setup is that I have two machines for the same purpose (gateway, in 
this case), one in standby and one active. Things are setup that services 
(routes, in this case) use an address that's an alias which the active machine 
has and the standby one lacks. Moving the service from one box to the other 
means deleting the alias address from the formerly active one and adding it on 
the formerly standby one.

This works in the IPv4 case because the newly active machine sends a GARP for 
the alias address, but it fails for IPv6. Is there a way to make it work for 
v6?

I'm aware others use CARP for this and just move the MAC address, but moving 
the IP address should work, too, no?