Re: [patch 23/32] IPV4: Correct rp_filter help text.

Herbert Xu
2007-06-09T01:21:17Z

Chris Wright <chrisw@sous-sol.org> wrote:
>
> --- linux-2.6.20.13.orig/net/ipv4/Kconfig
> +++ linux-2.6.20.13/net/ipv4/Kconfig
> @@ -43,11 +43,11 @@ config IP_ADVANCED_ROUTER
> asymmetric routing (packets from you to a host take a different path
> than packets from that host to you) or if you operate a non-routing
> host which has several IP addresses on different interfaces. To turn
> - rp_filter off use:
> + rp_filter on use:
>
> - echo 0 > /proc/sys/net/ipv4/conf/<device>/rp_filter
> + echo 1 > /proc/sys/net/ipv4/conf/<device>/rp_filter
> or
> - echo 0 > /proc/sys/net/ipv4/conf/all/rp_filter
> + echo 1 > /proc/sys/net/ipv4/conf/all/rp_filter

BTW, this documentation is actually wrong. You can't enable rp_filter
on all interfaces with

echo 1 > /proc/sys/net/ipv4/conf/all/rp_filter

You must do that in conjunction with

echo 1 > /proc/sys/net/ipv4/conf/<device>/rp_filter

for it to work for <device>.

This is really counter-intuitive but it's apparently how it's always
worked.

Cheers,
--
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Email: Herbert Xu ~{PmV>HI~} <herbert@gondor.apana.org.au>
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