单项选择题
A. BGP uses TCP port 179.
B. BGP ensures reliability of updates by using the reliable transport services of TCP.
C. The network command with the mask option never insta lls a prefix into the BGP table unless there is a matching prefix exists in the IP route table.
D. A TCP connection is required before exchanging updates.
E. BGPuses notification and the update messages to establish and maintain the BGP neighbor relati onship.
单项选择题 Refer to the exhibit. Which statement is true about the 6.6.6.0/24 prefix?（）
单项选择题 Which statement is true about IPv6?（）
单项选择题 Refer to the exhibit. Autonomous systems 200 and 300 have EBGP sessions established with their directly connected routers in au tonomous system 100. IGP has been configured on all routers in autonomous system 100 and they successfully exchange routing updates. Traffic originated in autonomous system 200 cannot reach the destination autonomous system 300. What configuration shoul d be done on the routers in autonomous system 100 in order for the traffic coming from autonomous system 200 to be forwarded to autonomous system 300?（）