Unable to access mysite with public url after configuring AAM

HI all

I am using sharepoint server 2010. I have (1app, 2wfe, 1sql) hosting our sp sites.There is an IntraNet portal site created on port 80
mysite is created on different webapplication using port 1111
I am able to access sites port 80 with AAM url.//sharepointportal
I am not able to access mysite with AAM url //sharepointportal:1111 (getting internet explorer cannot display the webpage). able to access with hostname.

Thanks in advance

Prasad.