Re: vnet problem (bug? feature?)

On 2/16/15 3:13 AM, Toerless Eckert wrote:

I fail to find a good reference explaining why linux would default to
rp_filtering = 1 (more appropriate for routers) even if forwarding defaults to 0
(more appropriate for multi-homed hosts).

It's a userspace default. For Fedora/Red Hat based systems see /etc/sysctl.conf (older releases) and /usr/lib/sysctl.d/50-default.conf (newer ones).

I recall it defaulting to 1 in the early 2000's so it has been that way for a long time.

From Documentation/networking/ip-sysctl.txt:

rp_filter - INTEGER
...
        Default value is 0. Note that some distributions enable it
        in startup scripts.

David