Question: In NDS/IP, what is the primary role of a Security Gateway (SEG) in relation to external security domains for NDS/IP traffic?
Option 1: To establish and maintain IPsec secured ESP Security Associations in tunnel mode between security domains.
Option 2: To negotiate finer-grained security granularity directly with external entities.
Option 3: To operate as a Network Element (NE) within the same security domain for internal communications.
Option 4: To bypass hop-by-hop security for direct communication between different security domains.
Explanation: According to NDS/IP architecture, Security Gateways (SEGs) engage in direct communication with entities in other security domains specifically for NDS/IP traffic. Their key function is to establish and maintain IPsec secured ESP Security Associations in tunnel mode between these security domains, ensuring hop-by-hop security protection for securing inter-domain communications.