[root@localhost ~]# host -t SRV _ldap._tcp.startn.com _ldap._tcp.startn.com has SRV record 10 0 389 authen.startn.com. [root@localhost ~]# dig authen.startn.com ; <<>> DiG 9.9.2-rl.028.23-P2-RedHat-9.9.2-10.P2.fc18 <<>> authen.startn.com ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 39385 ;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 1, ADDITIONAL: 2 ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 4096 ;; QUESTION SECTION: ;authen.startn.com. IN A ;; ANSWER SECTION: authen.startn.com. 86400 IN A 10.0.10.182 ;; AUTHORITY SECTION: startn.com. 86400 IN NS engine.startn.com. ;; ADDITIONAL SECTION: engine.startn.com. 86400 IN A 10.0.10.181 2013/5/4 Kevein Liu <liuyang3240@gmail.com>
you have SRV record in your DNS server?