Login problem for external facing portal

Hi Everybody,

We have recently made our portal an external facing one, and after that I came across the following problem:

When I try to connect to the portal (external)b2b.xx..com

I am getting the login page but <b>after entering the username and password I am getting the Login page refreshed , not showing any errors</b>.

However when I try to login thru Intranet link portaldev.xx.com:50000 I am able to login and work without any issues.

Apperciate your help if some body has come across a similar situation .

We are running on EP6 SP11 and IIS6.0.

Thanks,

Vasu.