gluster添加节点失败报错：No route to host

glusterfs 3.4.7和gluster3.6.4都会出现该问题。

服务器端执行添加peer命令报如下错误：
Probe returned with unknown errno 107

对应日志错误信息如下：
[2015-08-25 02:47:06.818281] I [glusterd-handler.c:1031:__glusterd_handle_cli_probe] 0-glusterd: Received CLI probe req node61 24007
[2015-08-25 02:47:06.818633] I [glusterd-handler.c:3198:glusterd_probe_begin] 0-glusterd: Unable to find peerinfo for host: node61 (24007)
[2015-08-25 02:47:06.831101] I [rpc-clnt.c:969:rpc_clnt_connection_init] 0-management: setting frame-timeout to 600
[2015-08-25 02:47:06.834441] I [glusterd-handler.c:3131:glusterd_friend_add] 0-management: connect returned 0
[2015-08-25 02:47:06.834631] E [socket.c:2276:socket_connect_finish] 0-management: connection to 192.168.111.81:24007 failed (No route to host)
[2015-08-25 02:47:06.834823] I [mem-pool.c:545:mem_pool_destroy] 0-management: size=588 max=0 total=0
[2015-08-25 02:47:06.834836] I [mem-pool.c:545:mem_pool_destroy] 0-management: size=124 max=0 total=0

网上有一些描述，都未能提供解决方案：
http://serverfault.com/questions/690894/glusterfs-centos-7-wont-start#
http://funwithlinux.net/2013/02/glusterfs-tips-and-tricks-centos/
http://blog.csdn.net/hanphy/article/details/8901604

其实根因是权限问题，gluster报错比较离谱。

解决方案：
关闭防火墙或开放gluster相关端口权限。