在局域网中仅某台主机上无法访问域名为www.ccc.com的网站（其他主机访问正常）,在该主机上执行ping命令时有显示信息如下：

某网络中PC1无法访问域名为www.aaa.cn的网站，而其他主机访问正常，在PC1上执行ping命令时有如下所示的信息：C:>ping www.aaa.cnPinging www.aaa.cn[202.117.112.36] with 32 bytes of data： .Reply from 202.117.112.36: Destination net unreachable.Reply from 202.117.112.36:Destination net unreachable.Reply from 202.117.1 12.36:Destination net unreachable.Reply from 202.1 17.112.36: Destination net unreachable.Ping statistics for 202.117.112.36:Packets: Sent=4,Received=4,Lost=O(0% loss),Approximate round trip tunes in milli-seconds:Minimum=0ms, Maximum=0ms, Average=0ms