谁能告诉我为什么会这样？我可以使用 host 和/或 nslookup 解析主机名，但正向查找不适用于 dig；反向查找做：
musashixxx@box:~$ host someserver
someserver.somenet.internal has address 192.168.0.252
musashixxx@box:~$ host 192.168.0.252
252.0.168.192.in-addr.arpa domain name pointer someserver.somenet.internal.
musashixxx@box:~$ nslookup someserver
Server: 192.168.0.253
Address: 192.168.0.253#53
Name: someserver.somenet.internal
Address: 192.168.0.252
musashixxx@box:~$ nslookup 192.168.0.252
Server: 192.168.0.253
Address: 192.168.0.253#53
252.0.168.192.in-addr.arpa name = someserver.somenet.internal.
musashixxx@box:~$ dig someserver
; <<>> DiG 9.8.1-P1 <<>> someserver
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 55306
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 0 …