My planned work on networking stack

[Andre Oppermann]

Ian Smith wrote:
> 
> [-current out of ccs, I'm not subscribed]
> 
> On Tue, 2 Mar 2004, Andre Oppermann wrote to Wes Peters:
> 
>  > > Wowsers.  I can't wait to hear more.  When do you expect to have a design
>  > > for the ARP stuff and TCP buffer sizing, since they are underway?
>  >
>  > The ARP stuff is pretty simple and is a hash list IP->MAC per ethernet
>  > (actually 802.1) broadcast domain.  The harder part is to move all the
>  > code to one place from it's various net/* and netinet/* files.  As a
>  > nice side effect we get per-MAC accounting (octets, frames) for free.
> 
> What about bridged interfaces that have a MAC, but no IP address?  I'm
> still trying to figure this one out for a (4.8-R) bridge that's working
> fine but still has some issues with ARP confusion and thus repeated ARP
> requests from the upstream / outside router, esp regarding broadcast UDP
> traffic, where the inside interface has the one IP and thus broadcast
> address, for broadcast packets delivered locally to the bridge's IP?

ARP will only be there if an IP address is configured on a interface.
A bridge doesn't need any ARP for its bridging functionality, it is
just relaying a frame from one side to the other.  To do that it
maintains a table with MAC addresses it sees on the particitpating
interfaces.  But that is entirely unreated to ARP which only does
IP->MAC mappings.

> I realise this is a bridge issue, but it's how it interacts with ARP.
> 
> The rest of this is well out of my league, but fascinating reading :)

-- 
Andre