When two BGP routes have identical attributes (MED, origin, AS path length, local preference), BGP uses the router ID as a tie-breaker. In this case, route 2 has a higher router ID (10.10.200.1 vs. 10.10.100.1). BGP will select the route with the higher router ID as the active route.

References:

Useful Juniper Commands.txt

Tech Ops Managed Router Juniper Install Guide

OSPF Protocol Basics:

OSPF (Open Shortest Path First) is a link-state routing protocol.

Routers exchange LSAs (Link-State Advertisements) to share topology information.

LSA Acknowledgment Mechanism:

OSPF uses a reliable mechanism to ensure LSAs are received.

When a router sends an LSA to a neighbor, it expects an acknowledgment (ACK).

If an ACK is not received within a certain period, the router will retransmit the LSA.

Acknowledgment Process:

LSAs are sent over OSPF ' s reliable transport, which ensures delivery through acknowledgments.

This mechanism helps to maintain consistent and up-to-date topology databases across routers.

References:

OSPF RFC 2328

Understanding OSPF Operations

Understanding IEEE 802.3af Standard:

IEEE 802.3af, also known as PoE (Power over Ethernet), specifies the standard for delivering power over Ethernet cables.

This standard allows devices like IP phones to receive power along with data over the same cable.

Maximum Power Allocation:

According to the IEEE 802.3af standard, the maximum power that can be delivered to a powered device is 15.4 watts.

This power is delivered over Category 5 (Cat 5) cables or higher.

EX Series Switches Compliance:

Juniper EX Series switches with PoE support adhere to the IEEE 802.3af standard.

Thus, each PoE port on these switches can allocate up to 15.4 watts to connected devices.

References:

IEEE 802.3af standard specifications

Juniper EX Series switch documentation

Understanding the Problem:

The requirement is to provide Layer 2 connectivity between campus sites using Ethernet switches through a metro Ethernet service provider who is using Q-in-Q tagging.

Design Considerations:

VXLAN Implementation:

VXLAN (Virtual Extensible LAN) can be used to extend Layer 2 networks over Layer 3 networks. It is often used to provide scalability and flexibility in modern data center networks. In this case, VXLAN could be used to encapsulate Layer 2 frames within UDP packets, allowing them to be transported over the service provider’s network.

S-Tag Configuration:

Q-in-Q tagging, also known as 802.1ad, involves an outer tag (S-Tag) and an inner tag (C-Tag). The service provider network uses the S-Tag to identify and segregate customer traffic. Therefore, each campus switch must have the correct S-Tag (300 in this case) configured to ensure the service provider can correctly handle and route the traffic.

References:

Juniper Networks: Understanding VXLAN

Configuring Q-in-Q Tagging

Understanding the Problem:

The ports between the access switches and the distribution switch are shutting down when the L2PT configuration is applied. This typically happens due to a mismatch in port configurations or protocol incompatibilities.

Examining the Configurations:

L2PT (Layer 2 Protocol Tunneling) allows tunneling of Layer 2 traffic, which includes protocols like STP (Spanning Tree Protocol), CDP (Cisco Discovery Protocol), VTP (VLAN Trunking Protocol), etc. over a Layer 2 network.

If the L2PT is applied on access ports, it may lead to conflicts or shut down the ports as access ports are typically not configured to handle Layer 2 protocol traffic beyond their designated VLAN.

Solution: Configure Trunk Ports:

By configuring the links between the access switches and the distribution switch as trunk ports, you allow multiple VLANs to be carried over a single physical link. Trunk ports can carry tagged traffic for multiple VLANs, which includes the tunneled Layer 2 protocols.

This setup prevents the ports from shutting down and enables the correct tunneling of Layer 2 protocols.

References:

Juniper Documentation on L2PT Configuration

Troubleshooting Layer 2 Protocol Tunneling Issues

https://www.juniper.net/documentation/us/en/software/junos/routing-policy/bgp/topics/example/bgp-advertise-peer-as.html

Type 1 routes are used for per-ES auto-discovery (A-D) to advertise EVPN multi-homing mode. Remote ToR leaf devices in the EVPN network use the EVPN Type 1 route type functionality to learn the EVPN Type 2 MAC routes from other leaf devices. In this route type ESI and the Ethernet Tag ID are considered to be part of the prefix in the NLRI. Upon a link failure between ToR leaf and end server VTEP withdraws Ethernet Auto-Discovery routes (Type 1) per ES. The Juniper EVPN multi-homing Ethernet Tag value is set to the VLAN ID for ES auto-discovery/ES route types. Mass Withdrawal - Used for fast convergence during link failure scenarios between leaf devices to the end server using Type 1 EAD/ES routes.