router（config）# ip defoult-network IP-Address <——动态缺省路由——>
router（config）# ip route 0.0.0.0 0.0.0.0 [ Next-Hop-Address | Local-Out-Port ] [Distace ] <——静态缺省路由——>
router（config）# ＾z
其它命令：
router# show version
router# show running-config
router# show startup-config
router# show flash
router# show interface [ Type Port ]
router# show buffers
router# show protocol
router# show mem
router# show stacks
router# show processes
router# show cdp entry [ Device-Name ] <——显示指定邻居三层信息——>
router# show cdp neighbors
router# show cdp neighbors detail <——显示所有邻居三层信息->
router# show ip router
router# show ipx router
router# show host
router# show ip protocol
router# show ip interface Type Port
router# show ipx interface Type Port
router# show ipx servers
router# show ipx traffic
router# show access-lists [ ACL-Number ]
router# show isdn status
router# show dialer <——查看ISDN拨号信息——>
router# show isdn active
router# show frame-relay pvc
router# show frame-relay map
router# show frame-relay lmi
router# erase startup-config
router# reload
router# setup
router# copy running-config startup-config
router# copy startup-config running-config
router# copy tftp running-config
router# copy running-config tftp
router# debug ipx routing activity
router# debug ipx sap
router# debug isdn q921
router# debug isdn q931
router# debug dialer
router# debug ip rip
router# clear interface bri
