10. Common Problems and Troubleshooting NIS

Here are some common problems reported by various users:

1. The libraries for 4.5.19 are broken. NIS won't work with it.
2. If you upgrade the libraries from 4.5.19 to 4.5.24 then the su command breaks. You need to get the su command from the slackware 1.2.0 distribution. Incidentally that's where you can get the updated libraries.
3. When a NIS server goes down and comes up again ypbind starts complaining with messages like:

            yp_match: clnt_call:
                        RPC: Unable to receive; errno = Connection refused
           
   

   and logins are refused for those who are registered in the NIS database. Try to login as root and kill ypbind and start it up again. An update to ypbind 3.3 or higher should also help.
4. After upgrading the libc to a version greater then 5.4.20, the YP tools will not work any longer. You need yp-tools 1.2 or later for libc >= 5.4.21 and glibc 2.x. For earlier libc version you need yp-clients 2.2. yp-tools 2.x should work for all libraries.
5. In libc 5.4.21 - 5.4.35 yp_maplist is broken, you need 5.4.36 or later, or some YP programs like ypwhich will segfault.
6. libc 5 with traditional NIS doesn't support shadow passwords over NIS. You need libc5 + NYS or glibc 2.x.
7. ypcat shadow doesn't show the shadow map. This is correct, the name of the shadow map is shadow.byname, not shadow.
8. Solaris doesn't use always privileged ports. So don't use password mangling if you have a Solaris client.