Re: Asymmetric traffic/topology

I cannot site specific marketing or survey data. What I shared was  
based on my own experience developing networking and security  
products including working on a commercial IPS product for over 5 years.

-J
On Nov 8, 2007, at 8:37 PM, snort user wrote:

> Jeremy,
>
> Do you have any reference for the information that you provided?
>
> Thanks
>
> On Nov 8, 2007 6:06 PM, Jeremy Bennett <[email protected]> wrote:
>> First there are three types of asymmetry in a network that can cause
>> problems for some times of IPS devices.
>>
>> 1. Connection-level asymmetry: This is the case where a given TCP
>> connection (up and down stream) is on a single network path but a
>> separate, identical connection may follow a different path. This is
>> very common and can cause problems for behavioral systems.
>>
>> 2. Flow-level asymmetry: This is the case where the upstream and
>> downstream flows in a TCP connection may follow different paths. This
>> can cause problems for behavioral systems and stateful packet-
>> inspection.
>>
>> 3. Packet-level asymmetry: This is the case packets within a flow may
>> be following different routes in a network. This can cause problems
>> for any IPS except for the most basic packet-filter.
>>
>> Now in my experience, #1 is very common in medium to large
>> enterprises that have built for scalability and redundancy. #2 is
>> common in load-balanced server farms. #3 is not extremely common but
>> does appear in some instances of a hot-hot redundancy deployment.
>>
>>
>> -J
>>
>>
>> On Nov 7, 2007, at 4:42 PM, snort user wrote:
>>
>>> Greetings.
>>>
>>> I am sure that most of you know about the asymmetric traffic/ 
>>> topology
>>> problem in relevance to
>>> IDS/IPS systems.
>>> ( By Asymmetric traffic/topology, I mean the case where client to
>>> server packets traverse a different path
>>> in your network compared to server to client packets. Hence the
>>> IDS/IPS see only one side of the conversation)
>>>
>>> I am trying to find out how wide this problem really is?
>>> Is it commonly seen in large / enterprise networks ?
>>>
>>> Any input is welcome.
>>>
>>> Thanks
>>>
>>> -------------------------------------------------------------------- 
>>> --
>>> --
>>> Test Your IDS
>>>
>>> Is your IDS deployed correctly?
>>> Find out quickly and easily by testing it
>>> with real-world attacks from CORE IMPACT.
>>> Go to http://www.coresecurity.com/index.php5?
>>
>>> module=Form&action=impact&campaign=intro_sfw
>>> to learn more.
>>> -------------------------------------------------------------------- 
>>> --
>>> --
>>>
>>
>>
>
> ---------------------------------------------------------------------- 
> --
> Test Your IDS
>
> Is your IDS deployed correctly?
> Find out quickly and easily by testing it
> with real-world attacks from CORE IMPACT.
> Go to http://www.coresecurity.com/index.php5? 
> module=Form&action=impact&campaign=intro_sfw
> to learn more.
> ---------------------------------------------------------------------- 
> --
>


------------------------------------------------------------------------
Test Your IDS

Is your IDS deployed correctly?
Find out quickly and easily by testing it 
with real-world attacks from CORE IMPACT.
Go to http://www.coresecurity.com/index.php5?module=Form&action=impact&campaign=intro_sfw 
to learn more.
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