在客户的路由器MSR 30 上查看到如下debug 信息: *0.87831022 IP/8/debug_icmp: ICMP Receive: ttl-exceeded(Type=11, Code=0), Src = 3.3.3.1, Dst = 3.3.3.2; Origi nal IP header: Pro = 1, Src = 3.3.3.2, Dst = 20.1.1.1, First 8 bytes = 080081FF ABD40004 *0.87833017 IP/8/debug_icmp: ICMP Receive: ttl-exceeded(Type=11, Code=0), Src = 3.3.3.1, Dst = 3.3.3.2; Origi nal IP header: Pro = 1, Src = 3.3.3.2, Dst = 20.1.1.1, First 8 bytes = 08007A2E ABD40005 据此可以推测_____(多选)