On Fri, 06 Jan 2012 11:12:03 -0600, Gáspár Lajos <swifty@xxxxxxxxxxx> 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 -- To unsubscribe from this list: send the line "unsubscribe netfilter" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html