Basic Info of OVS

Basic info of Open vSwitch

Here i will tell a basic or default setting about Open vSwitch

FLOW TABLES
By default if the OVS has 5 flows in the flows table by default which is

ethtype = 800 [Internet Protocol version 4 (IPv4)] // p 5

ethtype = 806 [Address Resulution Protocol (ARP)] // Arp has 2 flow but different priorities 5 & 40000

ethtype = 88cc [Link Layer Discovery Protocol (LLDP)] // p 40000 *Some controller use this protocols

ethtype = 8942 (Broadcast Domain Discovery Protocol (BDDP)] //p 40000 *Some controller use this protcol

*p = Priorities

CONNECTED SWITCH STATUS

$ dsudo ovs-vsctl show

*Every OF switch should say:

"is_connected: true"

HOW CONTROLLER AND OPENVSWITCH COMMUNICATE AT FIRST

Here i will explain how Controller communicate with OpenvSwitch to established the connection

1. OFPT_HELLO (BOTH)

Hello messages are exchanged between switch and controller upon connection start up.

It will sent the highest version of OF protocols have.

2. OFPT_FEATURES_REQUEST (Controller)

Controller reply the OFPT_HELLO (sent the hight OF protocol have) and sent a OFPT_FEATURES_REQUEST (Request identity (or DPID) and basic capabilities of a switch.

2. OFPT_FEATURES_REPLY (Switch)

Switch will reply the identity aka DPID (Datapath ID), buffers support and number of tables, and auxiliary_id=1 yes, or auxiliary_id=0 false. And lastly capabilities.

2. OFPT_BARRIER_REQUEST (Controller)

To ensure message dependencies have been met or to receive notification for completed question.

2. OFPT_BARRIER_RESPOND (Switch)

Switch reply back.

2. OFPT_ROLE_REQUEST (Controller)

Role-Request messages are used by the controller to set the role of it's OpenFlow channel, or query that role. This mostly useful when the switch connected to multiple controllers

OFPT_ROLE_REPLY (Switch)

Will sent the info about OFPCR_ROLE_EQUAL

OFPT_MULTIPART_REQUEST (Controller)

Will sent a OFPMP_DESC

OFPT_MULTIPART_REPLY

The switch will reply the description about the hardware switch

OFPT_METER_FEATURES (CONTROLLER)

To know if the switch support metering or limiting group feature request and port description request

OFPMP_METER_FEATURES (SWITCH)

The switch will reply the capabilities

WILL BE CONTINUE..

This page will update from time to time.