lame server resolving이 계속되는데..

네임서버를 돌리고 있는데요.
갑자기 로그에 lame server resolving 메시지가 가득 들어찹니다.
왜 이런 현상이 나타나는 걸까요?

WowLinux 7.3 + bind 9.2.1 입니다.

messages 파일의 일부를 올립니다.

May 20 15:11:15 ns2 named[9363]: lame server resolving 'newtl.com' (in 'newtl.com'?): 218.145.29.146#53
May 20 15:11:15 ns2 named[9363]: lame server resolving 'newtl.com' (in 'newtl.com'?): 218.145.29.145#53
May 20 15:11:15 ns2 named[9364]: lame server resolving 'newtl.com' (in 'newtl.com'?): 218.145.29.146#53
May 20 15:18:45 ns2 named[9365]: lame server resolving 'test1.com' (in 'test1.com'?): 158.152.1.65#53
May 20 15:18:46 ns2 named[9365]: lame server resolving 'test1.com' (in 'test1.com'?): 158.152.1.65#53
May 20 15:18:47 ns2 named[9364]: lame server resolving 'test1.com' (in 'test1.com'?): 158.152.1.65#53
May 20 15:18:48 ns2 named[9364]: lame server resolving 'test1.com' (in 'test1.com'?): 158.152.1.65#53
May 20 15:26:14 ns2 named[9365]: lame server resolving 'test1.com' (in 'test1.com'?): 158.152.1.65#53
May 20 15:26:15 ns2 named[9365]: lame server resolving 'test1.com' (in 'test1.com'?): 158.152.1.65#53
May 20 15:26:16 ns2 named[9364]: lame server resolving 'test1.com' (in 'test1.com'?): 158.152.1.65#53
May 20 15:26:17 ns2 named[9365]: lame server resolving 'test1.com' (in 'test1.com'?): 158.152.1.65#53
May 20 15:28:45 ns2 named[9363]: lame server resolving 'test1.com' (in 'test1.com'?): 158.152.1.65#53
May 20 15:28:46 ns2 named[9364]: lame server resolving 'test1.com' (in 'test1.com'?): 158.152.1.65#53
May 20 15:28:47 ns2 named[9364]: lame server resolving 'test1.com' (in 'test1.com'?): 158.152.1.65#53
May 20 15:28:51 ns2 named[9366]: lame server resolving 'test1.com' (in 'test1.com'?): 158.152.1.65#53
May 20 15:47:07 ns2 named[9364]: lame server resolving 'test1.com' (in 'test1.com'?): 158.152.1.65#53
May 20 15:47:08 ns2 named[9363]: lame server resolving 'test1.com' (in 'test1.com'?): 158.152.1.65#53
May 20 15:47:09 ns2 named[9364]: lame server resolving 'test1.com' (in 'test1.com'?): 158.152.1.65#53
May 20 15:47:10 ns2 named[9364]: lame server resolving 'test1.com' (in 'test1.com'?): 158.152.1.65#53
May 20 15:55:08 ns2 named[9363]: lame server resolving 'shopimage.hanmil.net.or.kr' (in 'net.or.kr'?): 218.232.110.133#53
May 20 15:55:12 ns2 named[9365]: lame server resolving 'shopimage.hanmil.net.or.kr' (in 'net.or.kr'?): 218.232.110.133#53
May 20 15:55:16 ns2 named[9364]: lame server resolving 'shopimage.hanmil.net.or.kr' (in 'net.or.kr'?): 218.232.110.133#53
May 20 15:55:29 ns2 named[9364]: lame server resolving 'shopimage.hanmil.net.or.kr' (in 'net.or.kr'?): 218.232.110.133#53
May 20 15:55:37 ns2 named[9363]: lame server resolving 'shopimage.hanmil.net.or.kr' (in 'net.or.kr'?): 218.232.110.133#53
May 20 15:58:54 ns2 named[9365]: lame server resolving 'test1.com' (in 'test1.com'?): 158.152.1.65#53
May 20 15:58:55 ns2 named[9365]: lame server resolving 'test1.com' (in 'test1.com'?): 158.152.1.65#53
May 20 15:58:56 ns2 named[9363]: lame server resolving 'test1.com' (in 'test1.com'?): 158.152.1.65#53
May 20 15:58:56 ns2 named[9364]: lame server resolving 'test1.com' (in 'test1.com'?): 158.152.1.65#53
May 20 16:00:40 ns2 named[9366]: lame server resolving 'shopimage.hanmil.net.or.kr' (in 'net.or.kr'?): 218.232.110.133#53
May 20 16:00:51 ns2 named[9366]: lame server resolving 'shopimage.hanmil.net.or.kr' (in 'net.or.kr'?): 218.232.110.133#53