Re: [PATCH net-next] Implement draft-ietf-6man-rfc4941bis

[Stephen Hemminger <stephen@networkplumber.org>]

On Wed, 8 Apr 2020 07:44:58 -0300
Fernando Gont <fgont@si6networks.com> wrote:

> Implement the upcoming rev of RFC4941 (IPv6 temporary addresses):
> https://tools.ietf.org/html/draft-ietf-6man-rfc4941bis-09
> 
> * Reduces the default Valid Lifetime to 2 days
>   This reduces stress on network elements, among other things
> 
> * Employs different IIDs for different prefixes
>   To avoid network activity correlation among addresses configured
>   for different prefixes
> 
> * Uses a simpler algorithm for IID generation
>   No need to store "history" anywhere
> 
> Signed-off-by: Fernando Gont <fgont@si6networks.com>
> ---
>  Documentation/networking/ip-sysctl.txt |  2 +-
>  include/net/addrconf.h                 |  2 +-
>  include/net/if_inet6.h                 |  1 -
>  net/ipv6/addrconf.c                    | 85 +++++++++++---------------
>  4 files changed, 38 insertions(+), 52 deletions(-)
> 
> diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt
> index ee961d322d93..db1ee7340090 100644
> --- a/Documentation/networking/ip-sysctl.txt
> +++ b/Documentation/networking/ip-sysctl.txt
> @@ -1807,7 +1807,7 @@ use_tempaddr - INTEGER
>  
>  temp_valid_lft - INTEGER
>  	valid lifetime (in seconds) for temporary addresses.
> -	Default: 604800 (7 days)
> +	Default: 172800 (2 days)

You can't change defaults for existing users without a really good
argument.