第3部分:使用Debug命令
　　
　　最后，我们来学习如何正确使用调试工具Debug，实验过程见监测清单2-4。
　　
　　监测清单2-4正确使用Debug
　　
　　Router#debug?
　　aaa AAA Authentication, Authorization and Accounting
　　access-expression Boolean access expression
　　adjacency adjacency
　　all Enable all debugging
　　apple Appletalk information
　　arap Appletalk Remote Access
　　arp IP ARP and HP Probe transactions
　　async Async interface information
　　backup Backup events
　　callback Callback activity
　　cca CCA activity
　　... (此处省略)
　　ip IP information
　　ipx Novell/IPX information
　　lapb LAPB protocol transactions
　　... (此处省略)
　　vtemplate Virtual Template information
　　x25 X.25, CMNS and XOT information
　　x28 X28 mode
　　
　　Router#debug ip ?
　　bgp BGP information
　　cache IP cache operations
　　cef IP CEF operations
　　cgmp CGMP protocol activity
　　dhcp CGMP protocol activity
　　drp Director response protocol
　　dvmrp DVMRP protocol activity
　　egp EGP information
　　eigrp IP-EIGRP information
　　error IP error debugging
　　flow IP Flow switching operations
　　ftp FTP dialogue
　　html HTML
　　http HTTP connections
　　icmp ICMP protocol activity
　　igmp IGMP information
　　interface IP interface configuration changes
　　mbgp MBGP information
　　mcache IP multicast cache operations
　　mpacket IP multicast packet debugging
　　mrm IP Multicast Routing Monitor
　　mrouting IP multicast routing table activity
　　msdp Multicast Source Discovery Protocol (MSDP)
　　mtag IP multicast tagswitching activity
　　nat NAT events
　　ospf OSPF information
　　packet General IP debugging and IPSO security transactions
　　peer IP peer address activity
　　pim PIM protocol activity
　　policy Policy routing
　　rip RIP protocol transactions
　　routing Routing table events
　　rsvp RSVP protocol activity
　　rtp RTP information
　　sd Session Directory(SD)
　　security IP security options
　　socket Socket event
　　tcp TCP information
　　tempacl IP temporary ACL
　　trigger-authentication Trigger authentication
　　udp UDP based transactions
　　wccp WCCP information
　　
　　Router#debug ip icmp
　　ICMP packet debugging is on
　　Router#ping 172.16.1.1
　　Type escape sequence to abort.
　　Sending5,100-byte ICMP Echos to 172.16.1.1,timeout is 2 seconds:
　　!!!!!
　　Success rate is 100 percent(5/5),round-trip min/avg/max=8/11/12ms
　　Router#
　　04:13:25:ICMP:echo rep