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Subject: Re: [PATCH net-next] ipv4: enable route flushing in network
 namespaces
To:     Christian Brauner <christian@brauner.io>, davem@davemloft.net,
        kuznet@ms2.inr.ac.ru, yoshfuji@linux-ipv6.org,
        netdev@vger.kernel.org
Cc:     linux-kernel@vger.kernel.org
References: <20190624132923.16792-1-christian@brauner.io>
From:   David Ahern <dsahern@gmail.com>
Message-ID: <56ed92eb-14db-789a-c226-cdf8a5862e61@gmail.com>
Date:   Mon, 24 Jun 2019 13:49:33 -0600
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On 6/24/19 7:29 AM, Christian Brauner wrote:
> Tools such as vpnc try to flush routes when run inside network
> namespaces by writing 1 into /proc/sys/net/ipv4/route/flush. This
> currently does not work because flush is not enabled in non-initial
> network namespaces.
> Since routes are per network namespace it is safe to enable
> /proc/sys/net/ipv4/route/flush in there.
> 
> Link: https://github.com/lxc/lxd/issues/4257
> Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
> ---
>  net/ipv4/route.c | 12 ++++++++----
>  1 file changed, 8 insertions(+), 4 deletions(-)
> 

why not teach vpnc to use rtnetlink and then add a flush option to
RTM_DELROUTE?