A.HostA is not on the same subnet as its default gateway
B.The address of SwitchA is a subnet address
C.The Fa0/0 interface on RouterA is on a subnet that cannot be used
D.The serial interfaces of the routers are not on the same subnet
E.The Fa0/0 interface on RouterB is using a broadcast address

A.access-list 101 in
B.access-list 101 out
C.ip access-group 101 in
D.ip access-group 101 out

A.access-list 101 deny tcp 192.168.1.128 0.0.0.15 192.168.1.5 0.0.0.0 eq 23  access-list 101 permit ip any any
B.access-list 101 deny tcp 192.168.1.128 0.0.0.240 192.168.1.5 0.0.0.0 eq 23  access-list 101 permit ip any any
C.access-list 1 deny tcp 192.168.1.128 0.0.0.255 192.168.1.5 0.0.0.0 eq 21  access-list 1 permit ip any any
D.access-list 1 deny tcp 192.168.1.128 0.0.0.15 host 192.168.1.5 eq 23  access-list 1 permit ip any any

A.IR
B.DSSS
C.FHSS
D.DSSS and FHSS
E.IR，F(xiàn)HSS，and DSSS

A.L2TP
B.IPsec
C.PPTP
D.RSA