简答题

172.16.1.5为什么不能访问172.16.1.3？

A.source IP address and the protocol （such as SSL，HTTPS，SSH）
B.the packet Time to Live and the source IP address
C.type of service header and DSCP value
D.destination IP address

A.An update packet with init flag set from a known， already established neighbor relationship was received by one of the routers.
B.The ARP cache was cleared.
C.The counters were cleared.
D.The IP EIGRP neighbor relationship was cleared manually.