Cisco Updated 350-501 Exam Questions and Answers by selena

 The configuration in the exhibit shows the implementation of Nonstop Forwarding (NSF) with OSPF. NSF is used to minimize the downtime of neighbor relationships during a Route Processor (RP) switchover. The nsf command enables NSF, and ietf specifies the use of the IETF standard for graceful restart in OSPF. The restart interval 90 sets the time, in seconds, within which the restarting router should complete its restart, helping to maintain uninterrupted forwarding despite the switchover.

References: Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR v1.0); Cisco SPCOR Training & Certification.

The correct configuration for extending the layer 2 domain between the company’s two locations involves setting up the interface with L2 transport, specifying the encapsulation method as dot1q with the VLAN tag of 12, and applying the appropriate rewrite ingress tag rules. This setup ensures that the VLAN tag is preserved across the service provider’s core, maintaining the layer 2 domain continuity.

References := Implementing and Operating Cisco Service Provider Network Core Technologies

Network Services Orchestrator (NSO) uses the YANG (Yet Another Next Generation) modeling language to provide a standardized way to automate network devices. YANG provides a powerful schema to model configuration and state data for network elements, which NSO leverages for service automation and orchestration.

References: Cisco Crosswork Network Services Orchestrator (NSO) - Cisco2.

• The BGPsec framework is designed to secure the AS path information in BGP updates. It uses digital signatures to validate the AS path and prevent unauthorized route manipulation. Here are the key points related to BGPsec:

• Securing AS Path:
• Private Keys and Router Key Pair:
• Expiration Time:

In summary, BGPsec enhances BGP security by securing the AS path using digital signatures and private keys. It does not rely on IPsec tunnels for security1.

References:

• Cisco. (2021). Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) v1.0. Cisco Learning Services.
• Cisco. (2021). Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) v1.1. Cisco Learning Network Store.
• Cisco. (2021). BGPsec Overview. Link