Within an IGP area, which two statements are correct? (Choose two.)

Within an IGP area, which two statements are correct? (Choose two.)
A . Routers summarize information they learn from neighbors.
B . Routers discard valid but inaccurate information from neighbors.
C . Routers advertise information about themselves.
D . Routers relay information delivered by neighbors.

View Answer

Answer: C, D

Explanation:

Within an IGP area, routers advertise information about themselves and relay information delivered by neighbors. This is how link-state routing protocols such as OSPF and IS-IS work. They flood information about the network topology to all routers in the same area or domain. That information is then used to build a complete network connectivity map and to calculate the shortest path to destinations. Routers do not summarize or discard information within an area, unless they are configured to do so by some filtering mechanism.

Reference: Ericsson IP Networking – Routing Protocols, IP Routing: ISIS Configuration Guide – IS-IS Overview and Basic Configuration