Re: don't interrupt traffic when snort inline crashes

[Kiet Tran <kietstar () gmail com>]

Hi Guillaume;

In normal operating condition, your system running snort
should be configured and behaved like a wire connecting
the networking traffic on both side. This means forwarding
packets should look exactly the same as when they enter
your system. This is sometimes called a transparent bridge.
ie, no vlan translation, no MAC address translation, etc.

Then, when the system fails into using the open NIC, network
packets will continued to be identical as if the snort
filter were still active. Except no filtering, the networking
equipments connected on both sides of the snort system will
be seeing the same packets as if the snort system was active.

Hope this helps.
Regards,
Kiet

On 4/13/2012 9:06 PM, Guillaume Daleux wrote:
> Hi all,
>
> We decided to use snort inline as an IPS.
>
> We will deploy snort inline on network and we have one question about what will happen when machine or snort will 
> crash.
>
> - If our machine crashes, we have a fail open card so traffic will be forward. (of course without IPS but we think 
> it's better to not interrupt network traffic)
> - My question is if snort crashes, the bridge between our interface will be broken but the system will be up so fail 
> open card will not work as a bridge and we will lost every packets.
>
> How could we resolve this issue to not interrupt traffic after snort crashes ?
>
>
> Thanks for your answer.
>
>
>
>
> Guillaume DALEUX
>       
> tel : 450.430.8166 x2279 | guillaume.daleux () abovesecurity com
>
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>
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>
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