[Ns-developers] [ns3] arp cache location

[Hagen Paul Pfeifer]

On Sun, 25 May 2008 19:28:01 -0700, Mathieu Lacage
<mathieu.lacage at sophia.inria.fr> wrote:

> What I know for sure is that the code should be written to handle a one
> to many relationship between a netdevice and multiple ipv4 interfaces.
> The question then, is whether we should maintain a single arp cache per
> ipv4 interface or a single arp cache per netdevice. I was too lazy today
> to look at the linux kernel to figure out what they chose: someone might
> know this offhand and reply :)

AFAIK there is _one_ neighbor cache per _host_ (or per netdevice). The
host resolve the addresses based on the device (neigh_lookup()) - I am
not sure if I understand the ns3 terminus correctly. FW should validate
this!

I also discovered a unusual ARP behavior: if two nodes within one network
communicate with each other both hosts perform a neighbor discovery,
though the "second" should already cache the arp/ip relationship.

> regards,
> Mathieu

HGN