[CentOS] why would ls, while or ci use NIS?

Wed Jun 21 18:34:43 UTC 2017
Dave Burns <tburns at hawaii.edu>

I have an entry in root's crontab:

#ls -1 /etc/RCS|sed "s~\(.*\),v~\1~"|while read file; do ls -la
/etc/$file|ci -q -l /etc/$file ;done

Error output I received:
do_ypcall: clnt_call: RPC: Unable to receive; errno = No route to host
YPBINDPROC_DOMAIN: Domain not bound
do_ypcall: clnt_call: RPC: Unable to receive; errno = No route to host
YPBINDPROC_DOMAIN: Domain not bound
do_ypcall: clnt_call: RPC: Unable to receive; errno = No route to host
YPBINDPROC_DOMAIN: Domain not bound
do_ypcall: clnt_call: RPC: Unable to receive; errno = No route to host
YPBINDPROC_DOMAIN: Domain not bound

This looks like NIS (DNS?) error output, but what could be invoking
anything that uses NIS or DNS in that command? ls, ci, and while don't need
it unless they are applied to some NFS mounted file, but this is executed
as root with a *local* home directory on *local* files, no need for YP. The
only hypotheses I can think of are "my copies of bash or ci have been
compromised" or "I am stupid".

Enlighten me, please.
Dave