Correct Answer: B,C,E
Explanation/Reference:
Explanation:
Intermediate System to Intermediate System (IS-IS) was designed as the routing protocol for ISO's CLNP described in IS0 10589. IS-IS is a Link State routing protocol akin to OSPF and was developed by DEC for use with DECnet Phase V It was originally thought that TCP/IP would gradually make way for the seven layer OSI architecture so an enhancement to IS-IS was developed called Integrated IS-IS also known as Dual IS-IS that could route both Connectionless-Mode Network Service (CLNS) as well as IP.
Cisco IOS supports IS-IS authentication on 3 different levels; between neighbors, area-wide, and domain- wide, where each can be used by themselves or together. summary-address address mask {level-1 | level-
1-2 | level-2} is used to configure IP address summarization.
References:
http://www.rhyshaden.com/isis.htm
http://mynetworkingwiki.com/index.php/Configuring_IS-IS