JN0-280 Dumps With Exact Questions and Answers

IBGP (Internal Border Gateway Protocol)is used to exchange routing information betweenrouters within the same AS (Autonomous System).

Step-by-Step Breakdown:

TTL of 255:

By default, IBGP sessions are established with aTTL (Time to Live)value of255. This allows IBGP neighbors to communicate over multiple hops within the AS without requiring any additional configuration.

Full Mesh Requirement:

IBGP requires alogical full meshbetween all IBGP routers to ensure that routing information is fully distributed within the AS. Since IBGP does not propagate routes learned from one IBGP peer to another by default, a full mesh topology is needed unlessroute reflectorsorBGP confederationsare used.

Juniper Reference:

IBGP Full Mesh: Juniper recommends using route reflectors in large networks to simplify IBGP full-mesh requirements.

EVPN (Ethernet Virtual Private Network)is a standard protocol used for building Layer 2 and Layer 3 VPNs over an IP or MPLS network. Thesignaling protocolused for EVPN isBGP(Border Gateway Protocol).

Step-by-Step Breakdown:

BGP as the EVPN Signaling Protocol:EVPN uses BGP to exchange MAC address reachability information between routers (PE devices). This enables devices to learn which MAC addresses are reachable through which PE devices, facilitating Layer 2 forwarding across an IP or MPLS core.

BGP Extensions for EVPN:BGP is extended with new address families (e.g., EVPN NLRI) to carry both MAC and IP address information, allowing for scalable and efficient multi-tenant network solutions.

Juniper Reference:

Junos EVPN Configuration: Juniper uses BGP as the control plane for EVPN to exchange MAC and IP route information between different data center devices.

The exhibit shows aFolded IP Clos Architecture, which is also referred to as a3-stage Closnetwork design. This architecture typically consists of two layers of switches:

Spine Layer: The top row of switches.

Leaf Layer: The bottom row of switches.

Step-by-Step Breakdown:

Clos Architecture:A 3-stage Clos network has two types of devices: spine and leaf. In this design, each leaf switch connects to every spine switch, providing a high level of redundancy and load balancing.

Stage Explanation:

Stage 1: The first set of leaf switches.

Stage 2: The spine switches.

Stage 3: The second set of leaf switches.

TheFolded Closarchitecture shown here effectively "folds" the 3-stage design by combining the ingress and egress leaf layers into one, reducing it to two visible layers, but still maintaining the overall3-stage architecture.

Juniper Reference:

IP Clos Architecture: The 3-stage Clos design is commonly used in modern data centers for high availability, redundancy, and scalability.