Subject: Re: RTM_ADD and overwriting arp entries
To: Jun-ichiro itojun Hagino <>
From: Bill Studenmund <>
List: tech-net
Date: 09/07/2001 10:19:36
On Sat, 18 Aug 2001, Jun-ichiro itojun Hagino wrote:

> >>	RTM_ADD will not overwrite an existing (partial) arp entry.
> >>	My guess is this behaviour was introduced around 1.4 with the
> >>	new media independent arp subsystem.
> 	are you saying that you still have the problem with netbsd-current?
> 	we have some behavior change, which allows us to flush cloned
> 	routing entries (typically ARP entries) on manipulation of non-cloned
> 	parents.

I think the problem is a little different. It's not that we're
manipulating the partent, it's we want to manipulate the clone.

Consider a boot server serving a machine that doesn't support arp in its
boot firmware (like my PowerMac beige G3). A partial arp entry will get
entered on the boot server, but not completed (as the booting machine
won't). That then makes it hard for other tools to come along and fix the

I think the change sounds quite good.

Take care,