nslookup不能用了

我配置了DNS，用nslookup出现以下提示
*** Can't find server name for address 61.185.115.193: Server failed
*** Can't find server name for address ::: No response from server
*** Default servers are not available
不知是什么原因？
Freebsd 4.9

whereis nslookup
nslookup: /usr/sbin/nslookup /usr/share/man/man8/nslookup.8.gz /usr/src/usr.sbin/nslookup
FreeBSD# /usr/sbin/nslookup http://www.sohu.com
Server: zsu.edu.cn
Address: 202.116.64.1

Non-authoritative answer:
Name: pagegrp1.sohu.com
Addresses: 61.135.132.172, 61.135.132.173, 61.135.132.174, 61.135.132.176
61.135.133.109, 61.135.145.47, 61.135.150.65, 61.135.150.66, 61.135.150.67
61.135.150.69, 61.135.150.74, 61.135.150.75, 61.135.150.145, 61.135.131.73
61.135.131.180, 61.135.131.183
Aliases: http://www.sohu.com

FreeBSD#

找到毛病了，反向解析文件写错了：）太粗心了：）