A. In ftP Activee, the server side tells the client which port it expects to send data on by commanding
"PORT"

B. FTP always uses a TCP session to transmit control information and data information

C. In ftP-style, the client completes the initialization of the TCP session for control and data

D. FTP always uses TCP port 21 to establish a data session and TCP port 20 to establish a control session

E. FTP always uses the TCP port to establish a data session and ICP port 21 to establish a control session

A. The router maintains a timeout timer for each group membership, refreshes the timer if the receiver host is received, and deletes the group membership if the timer times out

B. As soon as the leave message is received, the router immediately deletes the group membership

C. The router periodically sends a Query message, and after the receiver host receives the Query message, it reports a Report message

D. The router queries a specific group

A. R1, which exists in both Level-1 and Leve-2, can ping the interface address of R2 loopback0

B. No neighbor relationship can be established between R1 and R2

C. R there is a route to R2 loopback0 100

D. LSDB

A. Untrust Zone

B. Security zone

C. Local zone

D. Trust zone

A. BGP to establish a neighbor relationship needs to first interact with the link state information

B. BGP establishing neighbors must be configured with MD5 authentication

C. BGP routers that support autodiscovery neighbors

D. BGP needs to establish a UDP connection before establishing a neighbor