求助：NIS服务的问题

今天在做NIS服务的实验，搭建好服务器了，在用客户端使用yptest检测时发下如下问题，希望各位高手帮帮忙
[root@guangxin ~]# yptest
Test 1: domainname
Configured domainname is "t9021"

Test 2: ypbind
Used NIS server: pc1

Test 3: yp_match
WARNING: Internal NIS error (Map passwd.byname, key nobody)

Test 4: yp_first
WARNING: Request arguments bad (Map passwd.byname)

Test 5: yp_next
-- skipped --

Test 6: yp_master
WARNING: Internal NIS error (Map passwd.byname)

Test 7: yp_order
WARNING: Internal NIS error (Map passwd.byname)

Test 8: yp_maplist
group.byname
protocols.byname
group.bygid
services.byservicename
netid.byname
passwd.byname
hosts.byaddr
passwd.byuid
ypservers
hosts.byname
protocols.bynumber
rpc.bynumber
services.byname
mail.aliases
rpc.byname

Test 9: yp_all
WARNING: Internal NIS error (Map passwd.byname)
5 tests failed