[CentOS] routing multiple network cards on a single subnet

Wed Jan 20 22:14:44 UTC 2010
Les Mikesell <lesmikesell at gmail.com>

On 1/20/2010 4:08 PM, Robert Spangler wrote:
> On Wednesday 20 January 2010 13:57, Frank Cox wrote:
>
>>   On Wed, 2010-01-20 at 09:50 -0800, R-Elists wrote:
>>   >  ummm, why do the two different networks need an IP on the same
>>   >  subnet ?
>>
>>   I have had a number of people ask me why I want this arrangement, where
>>   I have two modems on a single outbound subnet.
>>
>>   This is (going to be) a server with limited upload bandwidth.  By having
>>   two outbound connections, I can use a round robin dns entry to share the
>>   load between the two connections and increase my capacity.
>
> Please be aware that DNS was not designed to do what you are doing.  Yes it
> will do a round-robin but is not connection aware.  Lose a link and you lose
> half of the connections even though one link is still active.

That depends on how the client reacts.  Browsers generally are sensible 
and if DNS returns multiple IP's where some don't respond, will retry 
the connection with the others.  Most other things aren't that bright.

-- 
   Les Mikesell
    lesmikesell at gmail.com