On 11/4/18 18:45, Rabadan, Jorge (Nokia - US/Mountain View) wrote:
> [JORGE] not sure what you mean by "negative caching". If you refer to the 
> ability of certain routers/servers to inject dummy MACs into the ARP caches 
> so that hosts stop ARPing for absent IPs, the solution actually may help, 
> since there is an option to suppress unknown ARP-Requests/NS flooding 
> explained in Section 4.5. Should you choose to enable this option on the 
> Proxy-ARP/ND functions of the PEs, you no longer flood unknown ARP-Requests, 
> and therefore there is no longer need to inject those dummy MAC addresses to 
> stop the flooding. A host may keep ARP'ing for an absent host, but at least 
> those messages won't bother the entire BD. I added this text in the security 
> section:
> --------------
>   "The procedures in this document reduce the amount of ARP/ND message
>    flooding, which in itself provides a protection to "slow path"
>    software processors of routers and Tenant Systems in large BDs. The
>    ARP/ND requests that are replied by the Proxy-ARP/ND function (hence
>    not flooded) are normally targeted to existing hosts in the BD.
>    ARP/ND requests targeted to absent hosts are still normally flooded,
>    however the suppression of Unknown ARP-Requests and NS messages
>    described in Section 4.5. can provide an additional level of security
>    against ARP-Requests/NS messages issued to non-existing hosts." 
> --------------

Thanks.  I re-read section 4.5, and I think this does indeed address my
comment.  The addition of this text is appreciated.

Joe

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