On Fri May 1 2009, Martin wrote:
> On Fri, 2009-05-01 at 08:54 -0700, Roderick A. Anderson wrote:
> > I'm asking for a clue stick here. First time I've run into this issue
> > ... hard. Be a few times where it took a bit for outbound traffic to
> > get a route but can't remember running into this problem.
> > The short question is: does the network/NIC _know_ which IP address it
> > is responding for when a ping request comes in or does it just respond
> > to the ping request at the MAC (hardware?) level?
The *NIC* responds to MAC address(es) -
The *network* - now that is a big question. ;)
There is a ARP cache in the kernel, but it *should* be rather short-lived.
Try arpping to help find out what is happening.
> Ping uses ICMP, which is a service running over IP, thus it is processed
> with the rest of the IP layer (in the kernel, unless you ahve a very
> expensive TCP/IP offload engine). This is layer 3, MAC is a link level
> (level 2) concept and thus independant of the processing of ICMP, beyond
> providing a packet connection.
> - Martin
Received on Fri May 1 17:15:57 2009