NSO, or Network Services Orchestrator, provides full lifecycle management of devices and services in a network. It is designed to automate the service lifecycle from design and creation through deployment and decommissioning, without the need for manual intervention. This includes configuration, activation, updating, and ultimately, removal of services.

In this scenario, BGP is used in the core of the service provider network, while OSPF serves as the PE-CE routing protocol. To ensure communication between CE1 and CE2, which are located in different geographical locations, it's essential for PE1 and PE2 to share routes. This can be achieved by configuring both PEs to mutually redistribute BGP and OSPF routes within the VRF dedicated for that customer, ensuring seamless communication between both customer endpoints. Reference: 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:
BGPsec ensures the integrity of the AS path by allowing routers to sign BGP updates using their private keys.
When a router originates a BGP route, it signs the AS path information with its private key.
Other routers can verify the signature using the corresponding public key.
This prevents malicious AS path modifications and ensures the authenticity of the advertised route.
Private Keys and Router Key Pair:
BGPsec relies on cryptographic keys for signing and verifying BGP updates.
Each router has a router key pair consisting of a private key and a corresponding public key.
The private key is kept confidential and is used for signing route updates.
The public key is distributed to other routers for verification.
Expiration Time:
Unlike regular BGP updates, BGPsec does not assign an expiration time (TTL) to route advertisements.
The absence of an expiration time ensures that the signed AS path remains valid until explicitly withdrawn.
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.
Reference:
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

In NetFlow export statistics, the BGP next hop information is not included by default. To include the BGP next hop in the export statistics, specific keywords related to BGP next hop must be configured with the version 9 NetFlow entry. This configuration allows for the measurement of network traffic on a per-BGP next hop basis, which is essential for detailed traffic analysis and accounting1. Reference: Configuring NetFlow BGP Next Hop Support for Accounting and Analysis - Cisco Systems1.

When configuring the 802.1q VLAN tag, the MTU must be increased by 4 bytes. This is because the 802.1Q tag adds an additional header to the Ethernet frame, which includes information such as the VLAN ID and priority. To accommodate this extra header without fragmenting the packet, the MTU must be increased accordingly2. Reference: Configure 802.1Q VLAN Tagging, 802.1q and MTU.