在浏览器中打不开Oracle 11gR2的企业管理器页面
最近在Vmware虚拟机中装了CentOS5+Oracle11gR2，刚装完的时候，可以通过https://192.168.80.11:1158/em访问企业管理器。
后来我修改了虚拟机的主机名称，之后就访问不了企业管理器，端口也被自动改成了5500，然后用5500端口同样也访问不了。
数据库也重启了，操作系统也重启，都没用。

[oracle@ora11gr2 oracle]$ cat /u01/oracle/install/portlist.ini 
Enterprise Manager Console HTTP 端口 (orcl) = 5500
Enterprise Manager 代理端口 (orcl) = 3938

[oracle@ora11gr2 oracle]$ emctl status dbconsole
Oracle Enterprise Manager 11g Database Control Release 11.2.0.1.0 
Copyright (c) 1996, 2009 Oracle Corporation. All rights reserved.
http://ora11gr2:5500/em/console/aboutApplication
Oracle Enterprise Manager 11g is running. 
------------------------------
Logs are generated in directory /u01/oracle/ora11gr2_orcl/sysman/log 

[oracle@ora11gr2 oracle]$ lsnrctl status
LSNRCTL for Linux: Version 11.2.0.1.0 - Production on 02-5月 -2011 20:06:34
Copyright (c) 1991, 2009, Oracle. All rights reserved.
正在连接到 (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=ora11gr2)(PORT=1521)))
LISTENER 的 STATUS
------------------------
别名 LISTENER
版本 TNSLSNR for Linux: Version 11.2.0.1.0 - Production
启动日期 02-5月 -2011 19:38:48
正常运行时间 0 天 0 小时 27 分 46 秒
跟踪级别 off
安全性 ON: Local OS Authentication
SNMP OFF
监听程序参数文件 /u01/oracle/network/admin/listener.ora
监听程序日志文件 /u01/diag/tnslsnr/ora11gr2/listener/alert/log.xml
监听端点概要...
  (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=ora11gr2)(PORT=1521)))
服务摘要..
服务 "orcl" 包含 1 个实例。
  实例 "orcl", 状态 READY, 包含此服务的 1 个处理程序...
服务 "orclXDB" 包含 1 个实例。
  实例 "orcl", 状态 READY, 包含此服务的 1 个处理程序...
命令执行成功

[oracle@ora11gr2 oracle]$ ps -ef | grep oracle
root 10877 4201 0 19:35 pts/0 00:00:00 su - oracle
oracle 10878 10877 0 19:35 pts/0 00:00:00 -bash
oracle 11021 1 0 19:37 ? 00:00:00 ora_pmon_orcl
oracle 11023 1 0 19:37 ? 00:00:00 ora_vktm_orcl
oracle 11027 1 0 19:37 ? 00:00:00 ora_gen0_orcl
oracle 11029 1 0 19:37 ? 00:00:00 ora_diag_orcl
oracle 11031 1 0 19:37 ? 00:00:00 ora_dbrm_orcl
oracle 11033 1 0 19:37 ? 00:00:00 ora_psp0_orcl
oracle 11035 1 0 19:37 ? 00:00:00 ora_dia0_orcl
oracle 11037 1 0 19:37 ? 00:00:02 ora_mman_orcl
oracle 11039 1 0 19:37 ? 00:00:00 ora_dbw0_orcl
oracle 11041 1 0 19:37 ? 00:00:00 ora_lgwr_orcl
oracle 11043 1 0 19:37 ? 00:00:00 ora_ckpt_orcl
oracle 11045 1 0 19:37 ? 00:00:00 ora_smon_orcl
oracle 11047 1 0 19:37 ? 00:00:00 ora_reco_orcl
oracle 11049 1 0 19:37 ? 00:00:00 ora_mmon_orcl
oracle 11051 1 0 19:37 ? 00:00:00 ora_mmnl_orcl
oracle 11053 1 0 19:37 ? 00:00:00 ora_d000_orcl
oracle 11055 1 0 19:37 ? 00:00:00 ora_s000_orcl
oracle 11094 1 0 19:38 ? 00:00:00 ora_arc0_orcl
oracle 11096 1 0 19:38 ? 00:00:01 ora_arc1_orcl
oracle 11098 1 0 19:38 ? 00:00:00 ora_arc2_orcl
oracle 11100 1 0 19:38 ? 00:00:00 ora_arc3_orcl
oracle 11116 1 0 19:38 ? 00:00:00 ora_qmnc_orcl
oracle 11130 1 0 19:38 ? 00:00:00 ora_cjq0_orcl
oracle 11133 1 0 19:38 ? 00:00:00 ora_q000_orcl
oracle 11137 1 0 19:38 ? 00:00:00 ora_q001_orcl
oracle 11162 1 0 19:38 ? 00:00:00 /u01/oracle/bin/tnslsnr LISTENER -inherit
oracle 12192 1 0 19:43 ? 00:00:00 ora_smco_orcl
oracle 12194 1 0 19:43 ? 00:00:00 ora_