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To ensure proper functioning within an MST (Multiple Spanning Tree) region, the following parameters must match across all switches:

Revision number:

The revision number identifies the version of the MST configuration. All switches within the same MST region must have the same revision number to ensure consistency.

MSTI-to-VLAN mapping:

The MSTI (Multiple Spanning Tree Instance) to VLAN mapping must be identical on all switches. This mapping ensures that each VLAN is assigned to the correct spanning tree instance.

Configuration name:

The configuration name (or region name) must be the same across all switches. This name uniquely identifies the MST region and must be consistent to ensure switches recognize they are part of the same region.

References:

The MSTP configuration requirements are detailed in Juniper network configuration guides and standards documents on MSTP​​​​.

For Multiple Spanning Tree Protocol (MSTP) to operate correctly, all switches in the same region must have the same VLAN to instance mapping, revision level, and configuration name. These parameters ensure that all switches interpret the MSTP configuration consistently.

References:

MSTP Configuration Guide, Juniper Networks

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

LLDP-MED (Link Layer Discovery Protocol-Media Endpoint Discovery) is an extension of LLDP (Link Layer Discovery Protocol) that provides additional functionalities specifically for voice over IP (VoIP) devices, including automatic negotiation of power requirements. This protocol is essential for automatically negotiating power with IP phones when they are connected to EX Series switches.

Steps:

Enable LLDP-MED:

set protocols lldp-med

Configure LLDP-MED on the interfaces:

set interfaces ge-0/0/0 unit 0 family ethernet-switching port-mode access

set interfaces ge-0/0/0 unit 0 family ethernet-switching interface-mode access

set interfaces ge-0/0/0 unit 0 family ethernet-switching vlan members default

set interfaces ge-0/0/0 unit 0 family ethernet-switching storm-control default

Commit the configuration:

References:

Useful Juniper Commands.txt

Tech Ops Managed Router Juniper Install Guide

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.

 Technology Overview:

Q-in-Q (802.1ad), also known as VLAN stacking, allows multiple VLAN tags to be inserted into a single frame. This enables the carrying of multiple VLANs across a single backbone, preserving the original VLAN tags across different network segments.

 Application in Scenario:

By using Q-in-Q, the existing VLANs of the acquired company can be encapsulated within a single VLAN tag. This technique is highly efficient for carrying VLANs across a corporate backbone without altering the existing addressing scheme and with minimal configuration changes.

 Configuration Example:

Juniper Configuration:

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set interfaces ge-0/0/1 unit 0 family ethernet-switching vlan-id 100

set interfaces ge-0/0/1 unit 0 family ethernet-switching vlan-id-list 100-200

set interfaces ge-0/0/2 unit 0 family ethernet-switching vlan-id 300

set interfaces ge-0/0/2 unit 0 family ethernet-switching vlan-id-list 300-400

This setup ensures that VLANs 100-200 on interface ge-0/0/1 and VLANs 300-400 on interface ge-0/0/2 are bundled together, achieving the desired encapsulation.

 References:

Detailed configuration and benefits are documented in the "network-mgmt.pdf" file, which outlines the necessary steps and considerations for deploying Q-in-Q​​.

Enabling LLDP-MED:

LLDP-MED (Link Layer Discovery Protocol - Media Endpoint Discovery) is an extension of LLDP specifically for VoIP devices.

It allows network devices to advertise and receive configuration information, such as VLAN IDs, from the network switch.

Voice VLAN Feature:

The voice VLAN feature on switches is designed to simplify the deployment of VoIP by automatically placing voice traffic on a designated VLAN.

Configuring the appropriate access interfaces and VLAN ID for voice traffic ensures that voice packets are prioritized and properly segmented from other types of traffic.

Configuration Steps:

Enable LLDP-MED on the appropriate access interfaces:

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set protocols lldp-med interface ge-0/0/0

Enable the voice VLAN feature and specify the VLAN ID:

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set ethernet-switching-options voip interface ge-0/0/0 vlan voice

set ethernet-switching-options voip interface ge-0/0/0 forwarding-class assured-forwarding

References:

Juniper documentation on LLDP-MED

Juniper EX Series switch configuration guide for voice VLAN