Client IP Address
                                                 Last update (2008-04-18 17:35:48)
                                                                                                                   Date added (2008-04-04 19:02:24)

Summary
There are several ways to find the client IP address from a session. The most common is SYS_CONTEXT('USERENV','IP_ADDRESS') function, but there is and UTL_INADDR.GET_HOST_ADDRESS.

SYS_CONTEXT can get a lot of arguments.
As far as it concerns UTL_INADDR.GET_HOST_ADDRESS to have it work you must do some modifications. Follow the examples:

SELECT DECODE(TRUNC(SYSDATE - LOGON_TIME), 0, NULL, TRUNC(SYSDATE - LOGON_TIME) || ' Days' || ' + ') ||
TO_CHAR(TO_DATE(TRUNC(MOD(SYSDATE-LOGON_TIME,1) * 86400), 'SSSSS'), 'HH24:MI:SS') LOGON,
v$session.SID, v$session.SERIAL#, v$process.SPID spid, v$session.process CLPRID,
v$session.USERNAME, STATUS, OSUSER, MACHINE, 
SYS_CONTEXT('USERENV','IP_ADDRESS') IP, 
v$session.PROGRAM, MODULE, action, SQL_HASH_VALUE,
'alter system kill session ' || '''' || v$session.SID || ', ' || v$session.SERIAL# || '''' || ' immediate;' kill_sql
FROM v$session, v$process
WHERE v$session.paddr = v$process.addr
ORDER BY logon_time ASC;

SELECT DECODE(TRUNC(SYSDATE - LOGON_TIME), 0, NULL, TRUNC(SYSDATE - LOGON_TIME) || ' Days' || ' + ') ||
TO_CHAR(TO_DATE(TRUNC(MOD(SYSDATE-LOGON_TIME,1) * 86400), 'SSSSS'), 'HH24:MI:SS') LOGON,
v$session.SID, v$session.SERIAL#, v$process.SPID spid, v$session.process CLPRID,
v$session.USERNAME, STATUS, OSUSER, MACHINE, 
UTL_INADDR.GET_HOST_ADDRESS (SUBSTR(machine,INSTR(machine,'')+1)) IP, 
v$session.PROGRAM, MODULE, action, SQL_HASH_VALUE,
'alter system kill session ' || '''' || v$session.SID || ', ' || v$session.SERIAL# || '''' || ' immediate;' kill_sql
FROM v$session, v$process
WHERE v$session.paddr = v$process.addr
ORDER BY logon_time ASC;