问题1：执行ping命令返回结果
Reply from 192.168.4.254: TTL expired in transit.
Reply from 192.168.4.254: TTL expired in transit.
问题2：
%May 30 12:39:42 2005 Quidway SYSM/5/IP MOVE:Slot=1;Rcv src IP 192.168.5.16 packet from port 6 but it's nexthop arp 192.168.5.16 with 0008-0dad-2914 resided in port 8
%May 30 12:52:44 2005 Quidway SYSM/5/IP MOVE:Slot=1;Rcv src IP 192.168.5.150 packet from port 6 but it's nexthop arp 192.168.5.150 with 0003-2508-aa39 resided in port 8
%May 30 12:52:47 2005 Quidway SYSM/5/IP MOVE:Slot=1;Rcv src IP 192.168.5.102 packet from port 6 but it's nexthop arp 192.168.5.102 with 0008-0dc5-8a64 resided in port 8
%May 30 12:55:16 2005 Quidway SYSM/5/IP MOVE:Slot=1;Rcv src IP 192.168.4.235 packet from port 8 but it's nexthop arp 192.168.4.235 with 000a-e642-4304 resided in port 6
%May 30 12:55:27 2005 Quidway SYSM/5/IP MOVE:Slot=1;Rcv src IP 192.168.5.140 packet from port 6 but it's nexthop arp 192.168.5.140 with 0000-39a9-bdf3 resided in port 8

俺觉的如果想让人帮你分析问题，最好是把问题的环境描述清楚，这样才有利于别人分析问题，仅仅是拿出问题的症状，相信没有多少人愿意去花精力先去琢磨你问题发生的环境，然后再模棱两可地去分析（除非这问题是很常见的，不用联系问题的环境）。

谢谢楼上兄弟的建议，俺觉得上面的现象跟产生问题的环境应该没有太多的联系，我只想问一下，产生上面现象的原因大概是什么

问题一应该是路由上环路了，从而不停的绕圈圈，直到TTL expire为止。

问题二应该是交换机上存在环路。