多项选择题
A. Router# ping 192.168.13.26
B. Router# debug access-list 172
C. Router# show open ports 192.168.13.26
D. Router# show access-list
E. Router# show ip interface
单项选择题 You are the network administrator at TestKing. You apply the following access list on the E0 outbound interface connected to the 192.168.1.8/29 LAN: access-list 21 deny tcp 192.168.1.8 0.0.0.7 eq 20 any access-list 21 deny tcp 192.168.1.8 0.0.0.7 eq 21 any What will the effect of this access list be?（）
单项选择题 A network administrator wants to add a line to an access list that will block only Telnet access by the hosts on subnet 192.168.1.128/28 to the server at 192.168.1.5. What command should be issued to accomplish this task?（）
多项选择题 What are some general guidelines regarding the placement of access control lists?（）