Cisco 350-501 - Implementing and Operating Cisco Service Provider Network Core Technologies (350-501 SPCOR)

Model-driven telemetry (MDT) utilizes YANG models to enable the subscription to specific data items that are streamed from network devices. This allows applications to receive near real-time updates without the need for traditional polling methods. MDT with YANG provides a more efficient and scalable way to monitor network devices by pushing updates to subscribers, which can specify the exact data they require2.

References: Configure Model-driven Telemetry on Cisco IOS-XE Devices with YANG Suite - Cisco2.

Flexible NetFlow improves on traditional NetFlow by providing more flexibility and efficiency in collecting and analyzing network flow data. In this specific configuration, the “mode random one-out-of-100” command is used, which means that only one out of every 100 packets is sampled. This leads to reduced CPU and memory utilization (Option A) because fewer packets are being processed. Additionally, because fewer packets are being analyzed (only one out of every 100), the number of packets to be analyzed is significantly reduced (Option D), leading to further efficiencies.

References :=

Implementing and Operating Cisco Service Provider Network Core Technologies

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The command channel-group 1 mode desirable configures the switch port to actively send PAgP packets to negotiate forming an EtherChannel. PAgP is a Cisco-proprietary protocol used in the automatic creation of EtherChannel links. When set to ‘desirable’, the port actively attempts to form an EtherChannel, which means it sends PAgP packets without waiting for the connected peer to initiate the negotiation.

References: For more information on link aggregation and EtherChannel configurations, refer to the Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) course materials, specifically the sections covering EtherChannel and PAgP.

IS-IS uses NET addresses to identify each router in the network, and the NET address of each router must be unique. In order for IS-IS to establish connectivity between R1 and R3, the NET address of R3 must be different from the NET address of R1, but it must also follow the same structure. In this case, the NET address of R1 is 49.0133.532b.ca14.6915.21311.F40F.1B3a.ba10.00, so the NET address of R3 must be 49.0133.532b.ca14.6915.21311.F40F.1B4a.bb87.00.

The ttl-security hops 2 command sets the accepted Time to Live (TTL) value for BGP packets received from a neighbor. It is used to protect against BGP session hijacking by ensuring that BGP packets come from an expected number of router hops away. In this case, the command specifies that BGP packets from neighbor 2.2.2.2 must have a TTL of at least 253, which means they can only be 1 hop away (255 - 2 = 253) to be accepted.

References: Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) training material1.