CCNP Service Provider 350-501 Book

 In IS-IS, Level 2 peers must have matching authentication settings to ensure security and integrity of the routing domain. The hello timer setting must also match to ensure that the peers can maintain a consistent adjacency state. Mismatched hello timers could lead to adjacency flaps or failure to form an adjacency.

References: The information is based on the IS-IS protocol’s use of TLVs (Type-Length-Value) which makes it highly extensible. As new features come in, they can be added to the protocol with TLVs. This includes authentication mechanisms and timer settings that ensure secure and stable adjacencies between Level 2 peers

The correct configuration for deploying VRF on ASBR router R1 to have connectivity over an MPLS VPN inter-AS Option AB network is found in option C. This involves configuring the interface with the commands shown, including setting the interface ethernet, applying IP VRF forwarding, and enabling MPLS BGP forwarding. These steps ensure that the interface is properly configured for VRF and can support MPLS VPN inter-AS communications effectively. References := Implementing and Operating Cisco Service Provider Network Core Technologies

• 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