PIX520 upgrade from 5.2(5) to 6.2(3) No DNS or internet access

[tleizear]

After upgrading our current PIX 520 w/failover to 6.2(5) we could not access the internet from the inside or dmz (seems to be a DNS problem), can't ping an outside address from a NAT address but can using a PAT address. HTTP Acces to the DMZ from the inside works fine. Are their any undocumented issues with using the config from a 5.2(5) on the new IOS level.

I have a test PIX setup with 6.2(3) loaded and have this working in a scaled down version, with the prodcution config loaded.

Any help wuold be appreciated.

[nkhawaja]

Hi,

We need to see your configs and syslog messages. Dont know and cant say much why DNS failed. The configs should work! You said, you can't ping an outside address from NAT address but can using a PAT address, what does that mean?

Thanks

Nadeem

[tleizear]

Nadeem,

The problem is resolved, the internet router on the pix outside interface was rebooted and this cleared the problem. Apparently without re-booting the router had old cached entries for the production PIX when we put the test pix online and thus the reply's to DNS and pings were not being delivered to the correct interface.