Linux NFS挂载时失败，报错：mount.nfs: Connection timed out

今天在转码业务平台挂载中兴分布式存储时，出现了挂载失败：linux-82ke:~ # mount -t nfs 192.168.202.60:/mnt/zxdfs/CM_South23/root/cccloud_tenant_id10001155 /mnt/D989/60/mnt/wfs10 -v
mount.nfs: timeout set for Wed Jul 30 15:39:52 2014
mount.nfs: trying text-based options "vers=4,addr=192.168.202.60,clientaddr=192.168.199.4"
mount.nfs: mount（2）: No such file or directory
mount.nfs: trying text-based options "addr=192.168.202.60"
mount.nfs: prog 100003, trying vers=3, prot=6
mount.nfs: trying 192.168.202.60 prog 100003 vers 3 prot TCP port 2049
mount.nfs: prog 100005, trying vers=3, prot=17
mount.nfs: trying 192.168.202.60 prog 100005 vers 3 prot UDP port 39325
mount.nfs: mount（2）: Connection timed out
mount.nfs: trying text-based options "vers=4,addr=192.168.202.60,clientaddr=192.168.199.4"
mount.nfs: mount（2）: No such file or directory
mount.nfs: trying text-based options "addr=192.168.202.60"
mount.nfs: prog 100003, trying vers=3, prot=6
mount.nfs: trying 192.168.202.60 prog 100003 vers 3 prot TCP port 2049
mount.nfs: prog 100005, trying vers=3, prot=17
mount.nfs: trying 192.168.202.60 prog 100005 vers 3 prot UDP port 32954
mount.nfs: mount（2）: Connection timed out
mount.nfs: trying text-based options "vers=4,addr=192.168.202.60,clientaddr=192.168.199.4"
mount.nfs: mount（2）: No such file or directory
mount.nfs: trying text-based options "addr=192.168.202.60"
mount.nfs: prog 100003, trying vers=3, prot=6
mount.nfs: trying 192.168.202.60 prog 100003 vers 3 prot TCP port 2049
mount.nfs: prog 100005, trying vers=3, prot=17
mount.nfs: trying 192.168.202.60 prog 100005 vers 3 prot UDP port 37809
mount.nfs: mount（2）: Connection timed out
mount.nfs: Connection timed out中兴分布式存储那边的/etc/exports配置为：
/data 192.168.199.*（rw,no_root_squash,sync,no_subtree_check）

但是奇怪的是，如果将/etc/exports修改为：
/data/test 192.168.199.4（rw,no_root_squash,sync,no_subtree_check）

挂载又是成功的。
最后无意间使用了如下配置后，居然正常了：
/data 192.168.199.0/24（rw,no_root_squash,sync,no_subtree_check）--------------------------------------分割线 --------------------------------------Ubuntu 12.04安装NFS server http://www.linuxidc.com/Linux/2012-09/70728.htmNFS服务器安装配置实现Ubuntu 12.04与ARM文件共享 http://www.linuxidc.com/Linux/2012-10/73159.htmUbuntu搭建nfs服务器 http://www.linuxidc.com/Linux/2012-10/71930.htm文件服务器NFS配置详解 http://www.linuxidc.com/Linux/2013-06/86542.htmUbuntu下搭建NFS网络文件系统服务器 http://www.linuxidc.com/Linux/2013-07/87367.htmHeartbeat_ldirector+LB+NFS实现HA及LB、文件共享 http://www.linuxidc.com/Linux/2013-06/85292.htmCentOS 5.5配置NFS服务器教程 http://www.linuxidc.com/Linux/2013-03/81737.htmUbuntu 12.10下NFS的安装使用 http://www.linuxidc.com/Linux/2013-03/80478.htm--------------------------------------分割线 --------------------------------------本文永久更新链接地址