One of the main resposibilities of ICMP is to report(1). Although technology has produced increasingly relaible transmission media, errors still exist and must be handled. IP is an(2)protocol. This means that error checking and error control are not a concern of IP. ICMP was designed, in part, to compensate for this shortcoming. Howerver, ICMP does not(3)errors, it simply report them. Error correction is left to the higher-level potocols. Error messages are always sent to the original(4)because the only information available in the datagram about the route is the source and destination IP addresses. ICMP use the source IP address to sent the error massage to the source of the(5).
- A.numbers
- B.functions
- C.strings
- D.errors
正确答案及解析
正确答案
D
解析
熟悉专业词汇，本题主要讨论ICMP协议。
