Trying to create a redundant or failover connection. Limited DNS knowledge.

[Dan]

Hello Everyone,

In my office, we have 2 T-1 connections.  We are using one as the main
internet line, and the other as a backup.  Our two most critical
systems are our webserver (which hosts our website) and our e-mail
server (MS Exchange 2000).  Each server has 2 NICs.  Each T-1 is on
its own firewall.  A big thing to consider is that we host our own
Website, Mailserver, and DNS.  Currently, all DNS records point to the
1st T-1 (subnet 4.20.35.x), so if outside parties try to access our
website or mailserver while our main T-1 is down, the name will not be
resolved correctly.  How can I set up the servers so that if one line
goes down, the other can pick up the slack including external DNS
resolution?  Or, must I use a hardware device to accomplish this type
of redundancy?

Thanks In Advance,
Dan