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SNMP4SDN Developer Guide

Overview

We propose a southbound plugin that can control the off-the-shelf commodity Ethernet switches for the purpose of building SDN using Ethernet switches. For Ethernet switches, forwarding table, VLAN table, and ACL are where one can install flow configuration on, and this is done via SNMP and CLI in the proposed plugin. In addition, some settings required for Ethernet switches in SDN, e.g., disabling STP and flooding, are proposed.

SNMP4SDN as an OpenDaylight southbound plugin

SNMP4SDN as an OpenDaylight southbound plugin

Architecture

The modules in the plugin are depicted as the following figure.

Modules in the SNMP4SDN Plugin

Modules in the SNMP4SDN Plugin

  • AclService: add/remove ACL profile and rule on the switches.
  • FdbService: add/modify/remove FDB table entry on the switches.
  • VlanService: add/modify/remove VLAN table entry on the switches.
  • TopologyService: query and acquire the subnet topology.
  • InventoryService: acquire the switches and their ports.
  • DiscoveryService: probe and resolve the underlying switches as well as the port pairs connecting the switches. The probing is realized by SNMP queries. The updates from discovery will also be reflected to the TopologyService.
  • MiscConfigService: do kinds of settings on switches
    • Supported STP and ARP settings such as enable/disable STP, get port’s STP state, get ARP table, set ARP entry, and others
  • VendorSpecificHandler: to assist the flow configuration services to call the switch-talking modules with correct parameters value and order.
  • Switch-talking modules
    • For the services above, when they need to read or configure the underlying switches via SNMP or CLI, these queries are dealt with the modules SNMPHandler and CLIHandler which directly talk with the switches. The SNMPListener is to listen to snmp trap such as link up/down event or switch on/off event.

Design

In terms of the architecture of the SNMP4SDN Plugin’s features, the features include flow configuration, topology discovery, and multi-vendor support. Their architectures please refer to Wiki (Developer Guide - Design).

Installation and Configuration Guide

Tutorial

Programmatic Interface(s)

SNMP4SDN Plugin exposes APIs via MD-SAL with YANG model. The methods (RPC call) and data structures for them are listed below.

TopologyService

  • RPC call
    • get-edge-list
    • get-node-list
    • get-node-connector-list
    • set-discovery-interval (given interval time in seconds)
    • rediscover
  • Data structure
    • node: composed of node-id, node-type
    • node-connector: composed of node-connector-id, node-connector-type, node
    • topo-edge: composed of head-node-connector-id, head-node-connector-type, head-node-id, head-node-type, tail-node-connector-id, tail-node-connector-type, tail-node-id, tail-node-type

VlanService

  • RPC call
    • add-vlan (given node ID, VLAN ID, VLAN name)
    • add-vlan-and-set-ports (given node ID, VLAN ID, VLAN name, tagged ports, untagged ports)
    • set-vlan-ports (given node ID, VLAN ID, tagged ports, untagged ports)
    • delete-vlan (given node ID, VLAN ID)
    • get-vlan-table (given node ID)

AclService

  • RPC call
    • create-acl-profile (given node ID, acl-profile-index, acl-profile)
    • del-acl-profile (given node ID, acl-profile-index)
    • set-acl-rule (given node ID, acl-index, acl-rule)
    • del-acl-rule (given node ID, acl-index)
    • clear-acl-table (given node ID)
  • Data structure
    • acl-profile-index: composed of profile-id, profile name
    • acl-profile: composed of acl-layer, vlan-mask, src-ip-mask, dst-ip-mask
    • acl-layer: IP or ETHERNET
    • acl-index: composed of acl-profile-index, acl-rule-index
    • acl-rule-index: composed of rule-id, rule-name
    • acl-rule: composed of port-list, acl-layer, acl-field, acl-action
    • acl-field: composed of vlan-id, src-ip, dst-ip
    • acl-action: PERMIT or DENY

FdbService

  • RPC call
    • set-fdb-entry (given fdb-entry)
    • del-fdb-entry (given node-id, vlan-id, dest-mac-adddr)
    • get-fdb-entry (given node-id, vlan-id, dest-mac-adddr)
    • get-fdb-table (given node-id)
  • Data structure
    • fdb-entry: composed of node-id, vlan-id, dest-mac-addr, port, fdb-entry-type
    • fdb-entry-type: OTHER/INVALID/LEARNED/SELF/MGMT

MiscConfigService

  • RPC call
    • set-stp-port-state (given node-id, port, is_nable)
    • get-stp-port-state (given node-id, port)
    • get-stp-port-root (given node-id, port)
    • enable-stp (given node-id)
    • disable-stp (given node-id)
    • delete-arp-entry (given node-id, ip-address)
    • set-arp-entry (given node-id, arp-entry)
    • get-arp-entry (given node-id, ip-address)
    • get-arp-table (given node-id)
  • Data structure
    • stp-port-state: DISABLE/BLOCKING/LISTENING/LEARNING/FORWARDING/BROKEN
    • arp-entry: composed of ip-address and mac-address

SwitchDbService

  • RPC call
    • reload-db (The following 4 RPC implemention is TBD)
    • add-switch-entry
    • delete-switch-entry
    • clear-db
    • update-db
  • Data structure
    • switch-info: compose of node-ip, node-mac, community, cli-user-name, cli-password, model