These is the list of default ports:
Daemon                   Default Port  Configuration Parameter
-----------------------  ------------ ----------------------------------
Namenode                 50070        dfs.http.address
Datanodes                50075        dfs.datanode.http.address
Secondarynamenode        50090        dfs.secondary.http.address
Backup/Checkpoint node?  50105        dfs.backup.http.address
Jobracker                50030        mapred.job.tracker.http.address
Tasktrackers             50060        mapred.task.tracker.http.address