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From: "Lloyd Standish" <lloyd@crnatural.net>
To: "Usuário do Sistema" <maiconlp@ig.com.br>,
	"Gáspár Lajos" <swifty@freemail.hu>
Cc: Andrew Beverley <andy@andybev.com>,
	Mail List - Netfilter <netfilter@vger.kernel.org>
Subject: Re: redundancy with Adsl modem
Date: Fri, 06 Jan 2012 12:16:39 -0600	[thread overview]
Message-ID: <op.v7oc11lrx1lyi3@debiandesk2.net> (raw)
In-Reply-To: <4F072B63.7060609@freemail.hu>

On Fri, 06 Jan 2012 11:12:03 -0600, Gáspár Lajos <swifty@freemail.hu> wrote:

> If the line goes down between step 2 and step 3 then the reply packet will never get back to B1 and A (because the line is down) !!!
> If the line goes down after step 4 then you can send it out on the second extrenal IP (B2 - 2.2.2.2) but C will see it as a NEW connection !!!
>So I think that your request is impossible on IP level.
> However you can use a proxy or a mail server, etc. etc. etc.

I think any sort of "uplink redundancy" such as "Usuario de Sistema" is looking for must be on the connection level, unless one is connecting to a server using some sort of link bonding or multilink protocol, which has to be supported on the gateway computer.  I have never done that.

My suggestions to Usuario for uplink redundancy assume that if an interface/uplink goes down, the connection *will* be broken, but any following connections will avoid the failed interface/uplink.  I think that is the best that can usually be done to provide Internet connection redundancy.  In my scenario, load-balancing is also performed by selecting the interface for NEW connection from the LAN to Internet at random.

-- 
Lloyd

  reply	other threads:[~2012-01-06 18:16 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-01-03  1:54 redundancy with Adsl modem Usuário do Sistema
2012-01-03  7:14 ` Andrew Beverley
2012-01-03 15:18   ` Usuário do Sistema
2012-01-03 23:58     ` Andrew Beverley
2012-01-04  0:17       ` Usuário do Sistema
2012-01-04  1:58     ` Lloyd Standish
2012-01-04  9:09       ` Gáspár Lajos
2012-01-04 11:16         ` Usuário do Sistema
2012-01-04 14:08         ` Lloyd Standish
2012-01-04 18:00           ` Gáspár Lajos
2012-01-04 20:15             ` Usuário do Sistema
2012-01-04 20:55               ` Lloyd Standish
2012-01-06 17:12               ` Gáspár Lajos
2012-01-06 18:16                 ` Lloyd Standish [this message]
2012-01-10  0:20                 ` Usuário do Sistema
2012-01-17 16:09                   ` Gáspár Lajos
2012-01-17 17:08                     ` Usuário do Sistema
2012-01-04 20:55             ` Lloyd Standish
2012-01-04 21:01             ` Lloyd Standish

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