Is 'Peer authentication' supported on HPUX ?

Hi,

Is 'Peer authentication' supported on HPUX ?  I am using PG 9.2 , where i have set

postgres1 postgres postgres  --> in pg_ident.conf

local all all ident map=postgresql1  --> in pg_hba.conf file

ident_file='/home/Postgresql/9.2/data/pg_ident.conf'  --> in postgresql.conf file

server got restarted successfully but at the time of connecting to user 'postgres' , i am getting this message :-

$ ./psql -U postgres postgres
2013-03-30 23:25:18 EDT LOG:  peer authentication is not supported on this platform
2013-03-30 23:25:18 EDT FATAL:  Peer authentication failed for user "postgres"
psql: FATAL:  Peer authentication failed for user "postgres"


Regards,
Tushar