Open Stack

On 11/11/15 10:30, JinXing F wrote:
>
> Hi, guys:
>
>     during the neutron installation guide, I found that we need to
> config the linux kernel as bellow: 
>
> net.ipv4.ip_forward=1
>
> net.ipv4.conf.all.rp_filter=0
>
> net.ipv4.conf.default.rp_filter=0
>
>
> the first one is the ip address translation between LAN and WLAN,
>

No, that's incorrect.  net.ipv4.ip_forward simply allows Linux to
forward IPv4 packets - i.e. to receive a packet on one network
interface, determine that it is not a packet that should be delivered
locally, and forward it on to its next IP hop.  There is no IP address
translation involved here.

> the second and third command is used for "Reverse Path Filtering".
>
> I cann't understand the purpose of the config in the neutron.
>

Do you mean that you don't understand what "Reverse Path Filtering" is? 
Or that you don't understand why Neutron needs RPF to be disabled?

For the former, please see
https://en.wikipedia.org/wiki/Reverse_path_forwarding.

Regards,
    Neil

> 1. If the instance in compute node connect with exteral network,what's
> the function of the three config?
>
> 2. The instance connect with each others, what's the function of the
> three config?
>
>
> I am very confused about this config.Please explain the answer to me. 
>
> Thanks. 
>