Two (2) DSL, 1 Zimbra server

[randall]

Hi All,

Here's my situation, I have 2 DSL lines and I have 1 Zimbra server (Dapper). I would like to utilize the 1st DSL line as my incoming and the 2nd DSL as my outgoing.

How do I set this up for my Zimbra server? (I have 2 NICs in my server already).

Thanks in advance for any helpful feedback.

[Klug]

How are your DSL lines connected to your network ?

[randall]

First scenario i would like to try is to connect the 2 DSL direct to the zimbra server. I would like to make it work first that way.

Then later on, I will try put it behind a firewall with a dual wan capability.

Basically, the 2 DSL will only be utilized by the Zimbra server, for now.

[misleb]

May I inquire as to the purpose of having 2 DSL lines like this? It seems like a rather arbitrary and problematic setup. I mean, it isn't like mail uses much bandwidth and even if it did, splitting incoming and outgoing wouldn't help because DSL is full duplex anyway. If this is for redundancy... well if you split incoming and outgoing mail, you're stuck if either one goes down.

The fundamental problem isn't really with Zimbra. It is IP routing. No matter what you do, your outgoing packets are always going to follow the default route out to the internet. So you could set one DSL line/IP as your primary MX, but the packets in response to connections will most likely go out the other DSL line if that is the default route. And you might have trouble with those packets getting out to the internet depending on how/if your ISP filters user packets sourced from a network not its own.

-matthew

[randall]

Hi Matthew,

Thank you for your response.

To clear things up, there is no problem with Zimbra.

The reason why we are thinking of splitting the incoming and outgoing line to 2 DSL lines is because of attachment issue. Our company send out rather a big attachment anywhere in the world, from our head office to our clients. And at the same we do receive big attachment too.

Yes I agree with you that DSL works full duplex, but in the country where we do our operation, Internet service is not so dependent. ISP's will either give you a good download rate or a good upload rate, even in a clear channel case (so sad). This basically, gave us the idea to split the sending and receiving if at all possible.

I would appreciate if you have a better suggestion than this..

Thanks again.

[misleb]

Linux can do some advanced routing. See http://lartc.org/howto/lartc.rpdb.multiple-links.html and Balancing Connections Over Multiple Links