Troy, Multihomed end points usually run BGP (Border Gateway Protocol). BGP allows you to advertise multiple paths to your network. Your mail server always has the same IP address, but BGP tells everyone that there are multiple paths to it and which ones are currently active. BGP can be very complicated or very simple depending on how you look at it and on the particular application.
Most multihomed end points are multihomed through different ISPs for redundancy. Running BGP in this case requires a public AS number, because it is advertised every where on the internet. It often requires a larger router (256 Mb) to handle all of the known routes on the internet. In your case, you have both of your connections from the same ISP. So you can run a private AS number. A private AS number is kind of like private IP addresses. I believe the private AS numbers are 64512 through 65535 (see http://www.arin.net). Running BGP requires a router capable of running BGP4, but because this is a private path, you only need to know the path to your ISP. So you can use a very small router. That small of a routing table should run on a Cisco 2500, 2600, or larger as long as the software version supports BGP4. An additional benefit for you, is that you could then load balance your T1s and gain full throughput through both of them to any IP address on your network Call your ISP and discuss this issue with them. They should be able to help you out. Mike ----- Original Message ----- From: "Troy D. Hilton" <[EMAIL PROTECTED]> To: "[EMAIL PROTECTED] ipswitch. com" <[EMAIL PROTECTED]> Sent: Thursday, March 04, 2004 2:44 PM Subject: [IMail Forum] Multihome IMail > Hello All, > > > > Is it possible to multihome an IMail server? Say for example, we have 2 > internet lines. If IMail is on LineA and LineA goes down we want it to > listen and respond on LineB. Can this be done with a single mailserver > that's multihomed? > > > > Troy > > To Unsubscribe: http://www.ipswitch.com/support/mailing-lists.html List Archive: http://www.mail-archive.com/imail_forum%40list.ipswitch.com/ Knowledge Base/FAQ: http://www.ipswitch.com/support/IMail/
