Slow Contacting my host behind NAT

[Karina Gómez Salgado]

Hi:

We are an ISP with a router Cisco 3640 and AS 5200's behind NAT. All of
our dial-up users  and some users of our internal network have address
192.168.0.X. They can see our inside web pages and external webpages
quickly without problem, but the connection to the mail and ftp server
is so slow.


When we don't have NAT in our routers and we used our public address in
our modems there wasn't problem, but now it takes a long time to contact
the server.

In our bind, the classes that we resolve are 200.33.20 and 207.3.141 and
i don't know if i have to add something about the 192.168 addresses.

I will appreciate any help,

Respectfully,

Karina Gomez
Btu Comunicacion