Where can I write apache configuration files?

Where can I write apache configuration files? -- Linux Enterprise Application-Linux server application information. For details, refer to the following section. Five DNSNAME, name1, name2, name3, name4, and name5 are available.
Two dns: example1.com.cn (Intranet) example2.com.cn (Internet)
A dnsname is applicable to a tomcat service.
Http://name1.example1.com.cn/
Http://name1.exmaple2.com.cn/
Http://name2.example1.com.cn/
Http://name2.exmaple2.com.cn/
All of the above are good. You can go to the apache test page. But when I configure 3, the Intranet is good,
Http://name3.example1.com.cn/# OK
Http://name3.example2.com.cn/# ERROR

Ask the Administrator to ping name3; name3.example1.com.cn; name3.example2.com.cn.
But I cannot find it by pinging it.
He said that my apache configuration is incorrect,
In addition to the master configuration file of/etc/httpd/conf/httpd. conf, I think there is also a configuration file in the relevant directory that has no other configuration files.