Since IBM does not ship a traceroute utility with OS/400, I   I wrote my own. Since it seems that this utility might be useful to other people as well, I've put it online.  Have Fun! 

NOTE: Due to the strict security features of OS/400, this utility requires a PTF to work on V4R4/V4R5, and will not work on V5R1 or later. In V5R1, IBM provides a TRACERT command that you should use instead.

• An AS/400 (iSeries/400) running an OS/400 version from V3R2 to V4R5
  
• Access to an account with *ALLOBJ authority (for installation)
  
• Your AS/400 needs to be running TCP/IP.
  
• You need an ILE RPG/400 compiler.
  
• To install on V4R4 or V4R5 you must install PTFs. Please see APARs MA21503 and MA21222 on IBM's iSeries Support site.
  
• IBM added a tracert utility to OS/400 in V5R1 and later. You'll want to use that, as mine will not work on those releases.
  

• Download my traceroute distribution and save it to your PC.

• Log onto your AS/400, and create a save file to store the store the distribution in. To do this, type CRTSAVF QGPL/TRACEROUTE

• FTP the distribution from your PC to your AS/400. To do this:
  • Open an MS-DOS Prompt.
    
  • Type: cd \directory\where\you\put\traceroute.savf
  • Type: ftp your-as400-name-here
    
  • Type: (enter your username & password when asked)
    
  • Type: binary
  • Type: put traceroute.savf QGPL/TRACEROUTE
  • Type: quit

• Back on the AS/400, type: RSTLIB SAVLIB(TRACEROUTE) DEV(*SAVF) SAVF(QGPL/TRACEROUTE)

• Build the CL program that will create everything needed to run traceroute. On your AS/400, type: CRTCLPGM TRACEROUTE/BUILDME SRCFILE(TRACEROUTE/SOURCE)

• Call the CL program to do the actual build. (For this you should be using an account with *ALLOBJ authority) CALL TRACEROUTE/BUILDME PARM(TRACEROUTE)

• Everything should now be compiled. Test it by typing ADDLIBLE TRACEROUTE followed by TRACEROUTE 'WWW.YAHOO.COM'

• Assuming everything is now working, you can delete the SAVF and the BUILDME program.

For more information see the README member of the file called "SOURCE" in the TRACEROUTE library.