Looking at the SOCKSVRC.NET.SYS, it reads

   compile & link commands with POSIX on MPE/iX 4.5

      ccxl <source>, <object>, <list>;info="-D_SOCKET_SOURCE -DPRE_47"
      link from=<object>;to=<program>;cap=ia,ba,ph; &
         rl=socketrl.net.sys,libcpx.lib.sys

HELP ccxl reads:

help ccxl
CCXL

     COMPILES AN HP C/XL PROGRAM.  HP C/XL IS NOT PART OF THE 900
     SERIES HP 3000 COMPUTER SYSTEM FUNDAMENTAL OPERATING
     SOFTWARE AND MUST BE PURCHASED SEPARATELY.  THIS COMMAND IS
     RECOGNIZED ONLY IF HP C/XL IS INSTALLED ON YOUR SYSTEM.
     (NM)

I think that the library you want is part of the C product.

>----------
>From:  Andrew Maxwell[SMTP:[log in to unmask]]
>Sent:  Friday, March 28, 1997 8:52 AM
>To:    [log in to unmask]
>Subject:       [HP3000-L] FW: Help compiling socket programs on 5.0
>
>----------
>
>> ----------
>From:  Robert Rose
>> I'm working with some simple sockets-based programs on my 3000 (5.0).
>> I've been able to work out the header file differences to get the code
>> to compile.  The problem I'm running into is getting the program to
>> link correctly.  Under the POSIX shell, when I compile, link and try to
>> run, I get the following:
>
>> UNRESOLVED EXTERNALS: socket  (LDRERR 512)
>> UNRESOLVED EXTERNALS: bind  (LDRERR 512)
>> UNRESOLVED EXTERNALS: listen  (LDRERR 512)
>> UNRESOLVED EXTERNALS: accept  (LDRERR 512)
>> Failed to locate the exported code symbol(s) for the imported code
>>symbol(s)
>
>> I checked out the NET.SYS group on my machine, and found
>> SOCKSVRC.NET.SYS.  The instructions for compiling and linking this
>> program refer to a library called libcpx.lib.sys.  I can't find this
>> file anywhere on my system.  Should it be there?
>
>> Thanks in advance, Bob Rose
>
>Can you try linking in SOCKETRL.NET.SYS ???
>
>Regards  Ken Vickers
>Computing Solutions Ltd
>