At 05:43 PM 8/18/98 +0800, william@pacific.net.ph wrote: ...

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Proposed Solution:

The 7010 router will be connected to the 2 ISPs. The 7010 will be upgraded to an IOS that supports NAT; all IP address behind the 7010 will be treated as internal IP addresses (to reduce reconfiguration). IP address subnets from both ISPs will be NAT-mapped to internal IP addresses over the 7010, including the DNS server and the mail server.

The DNS will be configured to use their DNS as the primary name server. The 2 ISPs' name servers will be used as secondary name servers.

The mail server will be configured to have 2 IP address, one actual and one virtual IP address using the network card. The DNS will have an MX 10 and an MX 20, each pointing to one IP addresses for the network card.

Is this solution possible? Will it work? Did I forget anything? Any tips?

That is one way to do it .. another and I think a BETTER way would be to only use 1 set of ip's ( a set that is "portable" ) and talk bgp with both providers. This way you can move the traffic in the most efficient way . If you take routes from both of em you may get a better path to site X from provider a and a better path to site Y from provider B .

This way if provider a goes down the BGP will move trafic of the link that is still "GOOD"

The NAT approach has the obvious advantage of being more "CIDR-friendly" to the "global Internet". It is probably somewhat more complicated, but if implemented correctly, it should provide reasonable redundancy and load- sharing just like a "portable" address space solution. --Vince