[RHEL5] Name resolution does not work.

Issue

• Our customer is encountering a problem that name resolution does not work.
• According to tcpdump, a query of DNS lookup was received. However, it seems that strace shows named did not receive it.

< tcpdump when 'nslookup xxxx' was performed by client >

11:19:04.057171 IP 10.2.206.68.2949 > 10.53.165.1.53: 5+ A? www.occ.ne.jp. (31)
11:19:42.993960 IP 10.2.206.68.2960 > 10.53.165.1.53: 6+ A? <a class="make_room_for_kcs" href="http://www.ellemoi.co.jp" target="_blank">www.ellemoi.co.jp</a>. (35)
11:20:06.889445 IP 10.2.206.68.2967 > 10.53.165.1.53: 7+ A? <a class="make_room_for_kcs" href="http://www.nesic.com" target="_blank">www.nesic.com</a>. (31)

< tcpdump when 'dig localhost xxxx' was performed on dns server >

11:21:39.216529 IP 127.0.0.1.53378 > 127.0.0.1.53: 19679+ A? www.occ.ne.jp. (31)
11:21:44.219116 IP 127.0.0.1.53378 > 127.0.0.1.53: 19679+ A? www.occ.ne.jp. (31)
11:21:49.221772 IP 127.0.0.1.53378 > 127.0.0.1.53: 19679+ A? www.occ.ne.jp. (31)
11:22:24.495248 IP 127.0.0.1.44559 > 127.0.0.1.53: 8002+ A? <a class="make_room_for_kcs" href="http://www.ellemoi.co.jp" target="_blank">www.ellemoi.co.jp</a>. (35)
11:22:29.497187 IP 127.0.0.1.44559 > 127.0.0.1.53: 8002+ A? <a class="make_room_for_kcs" href="http://www.ellemoi.co.jp" target="_blank">www.ellemoi.co.jp</a>. (35)
11:22:34.498840 IP 127.0.0.1.44559 > 127.0.0.1.53: 8002+ A? <a class="make_room_for_kcs" href="http://www.ellemoi.co.jp" target="_blank">www.ellemoi.co.jp</a>. (35)
11:22:57.106931 IP 127.0.0.1.50430 > 127.0.0.1.53: 63416+ A? <a class="make_room_for_kcs" href="http://www.nesic.com" target="_blank">www.nesic.com</a>. (31)
11:23:02.109098 IP 127.0.0.1.50430 > 127.0.0.1.53: 63416+ A? <a class="make_room_for_kcs" href="http://www.nesic.com" target="_blank">www.nesic.com</a>. (31)
11:23:07.110740 IP 127.0.0.1.50430 > 127.0.0.1.53: 63416+ A? <a class="make_room_for_kcs" href="http://www.nesic.com" target="_blank">www.nesic.com</a>. (31)

• According to the customer, it looks that the symptom disappered after updating /etc/hosts.
• The server in question is also working as a syslog server. However, customer did not define syslog clients in /etc/hosts and to a dns server until then. So, he configured them.