Which two statements are true regarding EIGRP authentication using a pre-shared key to generate an MD5 digest? (Choose two.)
- EIGRP authentication prevents attackers from establishing a neighbor relationship with a legitimate router.
- The key chain is referenced using the ip authentication key-chain command in global configuration.
- EIGRP authentication helps prevent Denial of Service (DoS) attacks.
- The MD5 hashing algorithm is the only option available for use with EIGRP authentication.
- EIGRP authenticates all EIGRP packets.
Explanation: When authentication is enabled, every packet exchanged between neighbors is authenticated to verify the neighbor's identity. This prevents unauthorized or malicious routers from forming adjacencies with legitimate routers. Note that the key chain is referenced in interface configuration mode (classic) or af-interface mode (named), not global configuration.
Related exam: Checkpoint Exam: Layer 3 Technologies – EIGRP
