WeOS
5.29.0

# FRNT HowTo

## About

This document details some common use-cases for FRNT and how to configure them.

For an overview of available configuration settings for FRNT refer to the configuration guide:

- FRNT Configuration Guide

## Introduction

The Fast Reconfiguration Network Topology Protocol (FRNT) handles fast reconfiguration in switched ring topologies. One of the switches has the role of FRNT focal point while the other switches are referred to as FRNT members. When the switches are connected in a ring, it is the responsibility of the focal point to break the loop by putting one of its ports (port ”M”) in blocking mode. When choosing FRNT ports, fixed speed and full duplex is recommended and also to avoid copper SFPs.

For information about using FRNT together with DHCP functionality in order to create a redundant network setup with dynamic address allocation, see:

- DHCP Relay Server Ring

## Single ring

The topology presented in this example consists of four different devices that create a redundant ring setup.

           .-------.               .-------.
           |       |M             N|       |
           |  S1   +-||------------+  S2   |
           |     fp|1             2|       |
           '---+---'               '---+---'
              2|N                     1|M
               |         FRNT          |
              1|M                     2|N
           .---+---.               .---+---.
           |       |N             M|       |
           |  S4   +---------------+  S3   |
           |       |2             1|       |
           '-------'               '-------'

Figure 1: FRNT network operating in ring mode.

### Configuration

Set up the focal point:

    S1:/#> configure
    S1:/config/#> ring
    S1:/config/ring/#> frnt
    S1:/config/ring/frnt/#> ports eth1, eth2
    S1:/config/ring/frnt/#> leave
    S1:/#>

Set up rest of the devices (S2 - S4), which aren’t focal points

    Sx:/#> configure
    Sx:/config/#> ring
    Sx:/config/ring/#> frnt
    Sx:/config/ring/frnt/#> no focal
    Sx:/config/ring/frnt/#> ports eth1, eth2
    Sx:/config/ring/frnt/#> leave
    Sx:/#>

Note

Double ring is not yet supported

## Bus

The main use case for configuring an FRNT bus is to achieve a horseshoe topology, by using the FRNT bus together with Ring Coupling. On the bus edges, only use port M.

      .-------.             .-------.             .-------.             .-------.
      |       |M           N|       |M           N|       |M           M|       |
      |  S1   +-||----------+  S2   +-------------+  S3   +-------------+  S4   |
      |     fp|1           2|       |1           2|       |1           2|       |
      '-------'             '-------'             '-------'             '-------'

Figure 2: FRNT network operating in bus mode.

### Configuration

Set up the focal point:

    S1:/#> configure
    S1:/config/#> ring
    S1:/config/ring/#> frnt
    S1:/config/ring/frnt/#> ports eth1
    S1:/config/ring/frnt/#> leave
    S1:/#>

Set up rest of the devices (S2 - S3), which aren’t focal points

    Sx:/#> configure
    Sx:/config/#> ring
    Sx:/config/ring/#> frnt
    Sx:/config/ring/frnt/#> no focal
    Sx:/config/ring/frnt/#> ports eth1, eth2
    Sx:/config/ring/frnt/#> leave
    Sx:/#>

Lastly set up the device that is at the end of the bus:

    S4:/#> configure
    S4:/config/#> ring
    S4:/config/ring/#> frnt
    S4:/config/ring/frnt/#> no focal
    S4:/config/ring/frnt/#> ports eth2
    S4:/config/ring/frnt/#> leave
    S4:/#>

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