Media for Destination NAT on PIX

Destination NAT on PIX

Hi all,

I'm trying to accomplish something, but I just can't get it to work.

The situation:

Internal network: 192.168.0.0 255.255.255.0 Old DNS servers: 150.159.216.202 and 150.159.216.206 New DNS servers: 205.171.3.65 and 205.171.2.65

We have to configure all the workstations to use new DNS-servers (yes I know, DHCP would have been an solution, but internal politics...). This will take some time, so I'm looking for a way to silently re-write the destination on the PIX which is situated between the LAN and the Internet connection.

formatting link

I found that I should use the alias command. I added the following config to the PIX:

alias (inside) 150.159.216.202 205.171.3.65 255.255.255.255 alias (inside) 150.159.216.206 205.171.2.65 255.255.255.255

And I gave a clear xlate.

When we tested from a server which has the proper DNS IP adresses configured, we found out that DNS didn't work anymore. Whichever IP address we used (old or new), we didn't receive a response. As soon as I removed the commands and gave a clear xlate, the new DNS servers would respond again.

Am I missing something here? We use PIX Finesse 6.3(1).

TIA.

Ikke Mij