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+# SONiC IGMP Snooping
+# High Level Design Document
+#### Rev 0.2
+
+# Table of Contents
+ * [List of Tables](#list-of-tables)
+ * [Revision](#revision)
+ * [About This Manual](#about-this-manual)
+ * [Scope](#scope)
+ * [Definition/Abbreviation](#definitionabbreviation)
+ * [1 Feature Overview](#feature-overview)
+ * [1.1 Requirements](#requirements)
+ * [1.1.1 Functional Requirements](#functional-requirements)
+ * [1.1.2 Configuration and Management Requirements](#configuration-and-management-requirements)
+ * [1.1.3 Scalability Requirements](#scalability-requirements)
+ * [1.1.4 Warm Boot Requirements](#warm-boot-requirements)
+ * [1.2 Design Overview](#design-overview)
+ * [1.2.1 Basic Approach](#basic-approach)
+ * [1.2.2 L2MC Docker](#l2mc-docker)
+ * [1.2.3 SAI Overview](#sai-overview)
+ * [2 Functionality](#-functionality)
+ * [2.1 Target Deployment Use Cases](#target-deployment-use-cases)
+ * [2.2 Functional Description](#functional-description)
+ * [3 Design](#design)
+ * [3.1 Overview](#overview)
+ * [3.2 DB Changes](#db-changes)
+ * [3.2.1 CONFIG DB](#config-db)
+ * [3.2.2 APP DB](#app-db)
+ * [3.2.3 STATE_DB](#state-db)
+ * [3.3 Switch State Service Design](#switch-state-service-design)
+ * [3.3.1 L2mcOrch changes](#l2mcorch-changes)
+ * [3.4 Docker for L2MC](#docker-for-l2mc)
+ * [3.4 SAI](#sai)
+ * [3.6 CLI](#cli)
+ * [3.6.1 Data Models](#data-models)
+ * [3.6.2 Configuration Commands](#configuration-commands)
+ * [3.6.3 Show Commands](#show-commands)
+ * [3.6.4 Debug Commands](#debug-commands)
+ * [3.6.5 Rest API Support](#rest-api-support)
+ * [4 Flow Diagrams](#flow-diagrams)
+ * [4.1 IGMP Snooping Enable on VLAN](#igmp-snooping-enable-on-vlan)
+ * [4.2 Static L2MC add flow](#static-l2mc-add-flow)
+ * [4.3 Dynamic L2mc add flow](#dynamic-l2mc-add-flow)
+ * [4.4 Port Down flow](#port-down-flow)
+ * [4.5 Vlan member-port delete flow](#vlan-member-port-delete-flow)
+ * [4.6 STP State change flow](#stp-state-change-flow)
+ * [5 Error Handling](#error-handling)
+ * [6 Serviceability and Debug](#serviceability-and-debug)
+ * [7 Warm Boot Support](#warm-boot-support)
+ * [8 Scalability](#scalability)
+ * [9 Unit Test](#unit-test)
+ * [9.1 CLI Test Cases](#cli-test-cases)
+ * [9.2 Rest API Test Cases](#rest-api-test-cases)
+ * [9.3 Functional Test Cases](#functional-test-cases)
+ * [9.4 IGMPv1 V2 and V3 cases](#igmpv1-v2-and-v3-cases)
+ * [9.5 Warm Boot Test Cases](#warm-boot-test-cases)
+ * [9.6 Scalability Test Cases](#scalability-test-cases)
+
+# List of Tables
+[Table 1: Abbreviations](#table-1-abbreviations)
+
+# Revision
+| Rev | Date | Author | Change Description |
+|:---:|:-----------:|:------------------:|-----------------------------------|
+| 0.1 | 05/22/2019 | Ashok Krishnegowda| Initial version |
+| 0.2 | 06/25/2091 | Ashok Krishnegowda| Incorporated review comments |
+
+
+# About this Manual
+This document provides general information about IGMP Snooping feature implementation in SONiC.
+# Scope
+This document describes the functionality and high level design of IGMP Snooping feature in SONiC.
+
+
+# Definition/Abbreviation
+### Table 1: Abbreviations
+| Term | Meaning |
+|--------|--------------------------------------------------------|
+| IGMP | Internet Group Management Protocol |
+| PIM | Protocol Independent Multicast |
+| L2MC | Layer-2 Multicast |
+|Mrouter | Multicast router |
+
+# 1 Feature Overview
+The forwarding of multicast control packets and data through a Layer 2 device configured with VLANs is most easily achieved by the Layer 2 forwarding of received multicast packets on all the member ports of the VLAN interfaces. However, this simple approach is not bandwidth efficient, because only a subset of member ports may be connected to devices interested in receiving those multicast packets. In a worst-case scenario, the data would get forwarded to all port members of a VLAN with a large number of member ports, even if only a single VLAN member is interested in receiving the data. Such scenarios can lead to loss of throughput for a device that gets hit by a high rate of multicast data traffic.
+Internet Group Management Protocol (IGMP) snooping is a mechanism by which a Layer 2 device can effectively address this issue of inefficient multicast forwarding to VLAN port members. Snooping involves "learning" forwarding states for multicast data traffic on VLAN port members from the IGMP control (join/leave) packets received on them.
+When snooping is enabled on a VLAN, switch examines IGMP packets between hosts connected to network switches and multicast routers. Switch builds member list based on what it learns from the report and mrouter port based on IGMP queries or PIM hello packet from multicast router, the switch then forwards multicast traffic to those interfaces in the VLAN where interested receivers are present instead of flooding the traffic to all member ports of the VLAN.
+
+
+## 1.1 Requirements
+
+### 1.1.1 Functional Requirements
+ 1. Support IGMP Snooping for IGMP Version1 (IGMPv1), IGMPv2, IGMPv3.
+ 2. Support IPv4 based forwarding.
+ 3. Support IGMP fast leave.
+ 4. Support IGMP querier functionality.
+ 5. Support static and dynamic multicast router list.
+ 6. Aging of dynamic mrouter ports will be supported. Static mrouter ports will not timed out, they have to be un-configured explicitly.
+ 7. Support static multicast group configuration. Static l2mc entries will not timed out, they have to be un-configured explicitly.
+ 8. Support trapping IGMP and PIM Hello control packets to CPU.
+ 9. Support Link-layer topology changes (due to STP) and generate queries on all non-mrouter ports for faster convergence.
+ 10. Ability to enable the logging at different levels of the l2mcast module.
+
+
+### 1.1.2 Configuration and Management Requirements
+
+This feature will support CLI configurations with the new framework.
+ 1. Support CLI configurations as described in "Configuration Commands" section below
+ 2. Support show commands as described in "Show Commands" section below
+ 3. Support debug commands as described in "Debug Commands" section below
+ 4. Support openconfig REST API and gNMI
+
+### 1.1.3 Scalability Requirements
+
+SONiC IGMP Snoooping feature does not have scale limit, scale number varies based on ASIC supported number.
+
+The following L2MC entries scale will be tested to success on an ASIC with 512 L2MC group support,
+ 1. Snooping on maximum of 512 VLANs.
+ 2. Maximum of 512 L2MC entries.
+
+### 1.1.4 Warm Boot Requirements
+
+Dynamic and Static L2MC entries should persist across warm reboot with no traffic disruption to the active flows.
+Learning of new snooping entries and aging of existing L2MC entries will stop while the control plane is away.
+
+- To support planned system warm boot.
+- To support SWSS docker warm boot.
+- To support l2mc docker warm boot.
+
+## 1.2 Design Overview
+
+### 1.2.1 Basic Approach
+### 1.2.2 L2MC Docker
+A new L2mc docker will be created to support IGMP snooping.
+L2mc will host l2mcastMgr and l2mcastd, the details of the changes will be discussed in the design section below.
+
+### 1.2.3 SAI Overview
+The existing L2MC SAI interface APIs shall be used to support this feature and they are available at below location,
+[https://github.com/opencomputeproject/SAI/blob/master/inc/sail2mc.h](https://github.com/opencomputeproject/SAI/blob/master/inc/sail2mc.h)
+https://github.com/opencomputeproject/SAI/blob/master/inc/sail2mcgroup.h
+
+The detail of the changes will be discussed in the design section below.
+
+# 2 Functionality
+Refer to section 1
+## 2.1 Target Deployment Use Cases
+
+## 2.2 Functional Description
+Refer to section 1.1
+
+# 3 Design
+## 3.1 Overview
+
+
+
+
+
+__Figure 1: IGMP Snooping High Level Architecture__
+
+L2MC docker will host L2mcastMgr and L2mcastd process.
+
+L2mcastMgr process will handle following interactions,
+
+- L2mcastMgr subscribes to CONFIG_DB to get configuration changes, it gets VLAN info from STATE_DB, and STP state changes from APP_DB.
+- L2mcastMgr notifies all these DB updates to L2mcastd for protocol operation via unix domain socket.
+
+L2mcastd process will handle following interactions,
+
+- Linux kernel to processes dynamic IGMP and PIM hello packets and netlink events.
+- L2mcastd uses libevent for processing below incoming events from l2mcastMgr,
+ - CLI configurations
+ - STP state change
+ - VLAN configuration changes.
+- Timer events are generated every 100ms for handling IGMP protocol timers.
+- L2mcastSync handles L2MC entries update to APP_DB to be consumed by L2mcOrch.
+
+
+## 3.2 DB Changes
+This section describes the changes made to different DBs for supporting IGMP Snooping.
+
+### 3.2.1 CONFIG DB
+#### CFG_L2MC_TABLE
+
+ ;Store IGMP Snooping configuration per VLAN
+ ;Status: work in progress
+ key = CFG_L2MC_TABLE:"Vlan"vlanid
+ ;field = value
+ enabled = BIT ; Is the IGMP Snooping on VLAN enabled (1) or disabled (0)
+ querier = BIT ; Is the IGMP Snooping querier enabled (1) or disabled (0)
+ fast-leave = BIT ; Is IGMP fast leave enabled(1) or disabled (0)
+ version = 1*DIGIT ; IGMP Snooping Version ( Version 1 or 2 or 3, Default: 2)
+ query-interval = 5*DIGIT ; Query Interval Value (1 to 18000sec, Default:125sec)
+ last-member-query-interval = 5*DIGIT ; Last Member Query Interval Value (100 to 25500ms; Default: 1000ms)
+ query-max-response-time = 2*DIGIT ; Query Response Time (1 to 25sec, Default: 10sec)
+ mrouter = [0-max_ports]*port_name ; Multicast router ports
+
+
+#### CFG_L2MC_STATIC_TABLE
+ ;Store Static L2MC entry configuration per VLAN.
+ ;Status: work in progress
+ key = CFG_L2MC_STATIC_TABLE:"vlan"vlanid:source_address:group_address
+ ;field = value
+ member_ports = [0-max_ports]*port_name ; Multicast Group Member Ports.
+
+### 3.2.2 APP DB
+
+#### APP_L2MC_VLAN_TABLE
+ ;Store Snooping state on VLAN
+ ;Status: work in progress
+ key = APP_L2MC_VLAN_TABLE:"Vlan"vlanid
+ ;field = value
+
+#### APP_L2MC_ENTRY_TABLE
+ ;Store L2MC entry per VLAN.
+ ;Status: work in progress
+ key = APP_L2MC_ENTRY_TABLE:"Vlan"vlanid:source_address:group_address
+ ;field = value
+ type = "static"/"dynamic" ; Static or Dynamic multicast group entry
+ member_ports = [0-max_ports]*port_name ; Multicast group member ports.
+
+### 3.2.3 STATE DB
+
+ No changes
+
+### 3.2.4 ASIC DB
+### 3.2.5 COUNTER DB
+
+ No changes
+
+## 3.3 Switch State Service Design
+### 3.3.1 L2mcOrch changes
+L2mcOrch is responsible for the following activities:
+ - Handles snooping enable/disable on VLAN being subscriber to APP_DB.
+ - For l2mc entry table changes, handles creation/deletion of l2mc entry being subscriber to APP_DB.
+ - For already existing l2mc entry, updates l2mc entry with changed member list.
+ - Translates these updates to SAI objects and pushes them to ASIC_DB.
+ - Creates l2mc db entry with OID mapping to handle subsequent l2mc entry member addition or deletion.
+
+## 3.4 Docker for L2MC
+A separate docker named 'l2mc' is created, It can be stopped/started/restarted independently. By default L2MC docker service will be disabled. When l2mcast docker is stopped, all the static and dynamic learnt l2mc entries are removed from the APP_DB and ultimately from the hardware.
+
+```
+root@sonic:/home/admin# docker ps
+CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
+9ff843cc79fa docker-syncd-brcm:latest "/usr/bin/supervisord" About a minute ago Up About a minute syncd
+042faedb7b4b docker-dhcp-relay:latest "/usr/bin/docker_iniâ¦" About a minute ago Up About a minute dhcp_relay
+210f0ad0b776 docker-router-advertiser:latest "/usr/bin/supervisord" About a minute ago Up About a minute radv
+b45498e6e705 docker-orchagent-brcm:latest "/usr/bin/supervisord" About a minute ago Up About a minute swss
+a77dbe67649a docker-l2mc:latest "/usr/bin/supervisord" 2 minutes ago Up About a minute l2mc
+0d3b86e300f9 docker-lldp-sv2:latest "/usr/bin/supervisord" 2 minutes ago Up About a minute lldp
+f65865e90fd1 docker-platform-monitor:latest "/usr/bin/supervisord" 2 minutes ago Up About a minute pmon
+4374ebb6e0e1 docker-teamd:latest "/usr/bin/supervisord" 2 minutes ago Up About a minute teamd
+6244613730fb docker-fpm-frr:latest "/bin/sh -c '/usr/biâ¦" 2 minutes ago Up About a minute bgp
+9ba9d3e63426 docker-database:latest "/usr/bin/supervisord" 2 minutes ago Up 2 minutes database
+```
+
+## 3.5 SAI
+L2MC SAI interface APIs are already defined, table shown below represents the SAI attributes which shall be used for IGMP Snooping.
+
+###### Table 2: L2MC SAI attributes
+| L2MC component | SAI attributes |
+|--------------------------|-------------------------------------------------------|
+| VLAN | SAI_VLAN_ATTR_CUSTOM_IGMP_SNOOPING_ENABLE
+| L2MC ENTRY | SAI_L2MC_ENTRY_ATTR_OUTPUT_GROUP_ID
+| L2MC Group | SAI_L2MC_GROUP_ATTR_L2MC_OUTPUT_COUNT
SAI_L2MC_GROUP_ATTR_L2MC_MEMBER_LIST
+| L2MC Group Member | SAI_L2MC_GROUP_MEMBER_ATTR_L2MC_GROUP_ID
SAI_L2MC_GROUP_MEMBER_ATTR_L2MC_OUTPUT_ID
+| L2MC Traps | SAI_HOSTIF_TRAP_TYPE_IGMP_TYPE_QUERY
SAI_HOSTIF_TRAP_TYPE_IGMP_TYPE_LEAVE
SAI_HOSTIF_TRAP_TYPE_IGMP_TYPE_V1_REPORT
SAI_HOSTIF_TRAP_TYPE_IGMP_TYPE_V2_REPORT
SAI_HOSTIF_TRAP_TYPE_IGMP_TYPE_V3_REPORT
SAI_HOSTIF_TRAP_TYPE_PIM
+
+
+IGMP Snooping feature can be enabled/disabled at VLAN level. By default the IGMP Snooping feature is disabled in SONiC. SAI_VLAN_ATTR_CUSTOM_IGMP_SNOOPING_ENABLE attribute can be set in the VLAN attributes using **set_vlan_attribute**
+
+The L2MC traps are enabled on the host interfaces to trap IGMP and PIM control packets to the CPU.
+
+To support programming of l2mc entry with list of member ports, current SAI object model of l2mc allows programming multiple member ports for a given L2MC entry, this is achieved using L2mc group object (SAI_L2MC_ENTRY_ATTR_OUTPUT_GROUP_ID) on the L2MC entry.
+L2mc group then has list of L2mc group members each of which points to a member port.
+
+### 3.5.1 COPP_TABLE TRAPS
+
+We have below set of IGMP and PIM traps already defined,
+
+ {"igmp_query", SAI_HOSTIF_TRAP_TYPE_IGMP_TYPE_QUERY},
+ {"igmp_leave", SAI_HOSTIF_TRAP_TYPE_IGMP_TYPE_LEAVE},
+ {"igmp_v1_report", SAI_HOSTIF_TRAP_TYPE_IGMP_TYPE_V1_REPORT},
+ {"igmp_v2_report", SAI_HOSTIF_TRAP_TYPE_IGMP_TYPE_V2_REPORT},
+ {"igmp_v3_report", SAI_HOSTIF_TRAP_TYPE_IGMP_TYPE_V3_REPORT},
+ {"pim", SAI_HOSTIF_TRAP_TYPE_PIM},
+
+
+IGMP and PIM protocol trap support will be added to enable trapping of IGMP query/leave/ v1,v2,v3 reports and PIM control packets.
+
+ "COPP_TABLE:trap.group.igmp”: {
+ "trap_ids": “igmp_query, igmp_leave, igmp_v1_report, igmp_v2_report, igmp_v3_report”,
+ "trap_action":"trap",
+ "trap_priority":"4",
+ "queue": "4",
+ "meter_type":"packets",
+ "mode":"sr_tcm",
+ "cir":"600",
+ "cbs":"600",
+ "red_action":"drop"
+ }
+
+ "COPP_TABLE:trap.group.pim”: {
+ "trap_ids": “pim”,
+ "trap_action":"trap",
+ "trap_priority":"4",
+ "queue": "4",
+ "meter_type":"packets",
+ "mode":"sr_tcm",
+ "cir":"600",
+ "cbs":"600",
+ "red_action":"drop"
+ }
+
+## 3.6 CLI
+### 3.6.1 Data Models
+Openconfig Yang model will be introduced for this feature.
+
+https://github.com/openconfig/public/blob/master/release/models/multicast/openconfig-igmp.yang
+
+### 3.6.2 Configuration Commands
+
+#### 3.6.2.1 Enable IGMP Snooping on VLAN
+
+**switch# config terminal**
+
+**switch(config)# vlan vlan-id**
+
+This command allows to configure IGMP Snooping on VLAN.
+
+**switch(config-vlan)# ip igmp snooping**
+
+
+#### 3.6.2.2 Enable IGMP Snooping Querier on VLAN
+The IGMP snooping querier sends out IGMP queries to trigger IGMP responses from devices receiving IP multicast traffic. The IGMP snooping querier listens for these responses to map the appropriate forwarding addresses.
+
+Below configuration allows to configure IGMP Snooping querier on VLAN.
+
+**switch(config-vlan)# ip igmp snooping querier**
+
+#### 3.6.2.3 Enable fast-leave
+
+**switch(config-vlan)# ip igmp snooping fast-leave**
+
+#### 3.6.2.4 Configure query-interval
+This command allows modification of the query interval to specify how often the querier sends general queries. The valid range is from 1 through 18000 seconds. The default is 125 seconds.
+
+**switch(config-vlan)# ip igmp snooping query-interval **
+
+#### 3.6.2.5 Configure last member query interval
+When the querier receives an IGMP leave message, it verifies the multicast group has no remaining listeners by sending a set of group-specific queries at a configured interval. If the querier does not receive a response to the queries, it removes the group state and stops forwarding multicast traffic.
+This command configures the transmission interval for sending group-specific or group-source-specific query messages to the active interface.
+The valid range is from 100 to 25500ms. The default is 1000ms.
+
+**switch(config-vlan)# ip igmp snooping last-member-query-interval **
+
+#### 3.6.2.5 Configure max response interval
+The Max Response interval field in a membership query messages specifies the longest time a host can wait before responding with a membership report message.
+Use the following commands to set the maximum response time and Value range from 1 to 25 seconds. The default is 10 seconds.
+
+**switch(config-vlan)# ip igmp snooping query-max-response-time **
+
+#### 3.6.2.6 Configure IGMP version
+
+This command allows to configure IGMP versions 1 through 3. A VLAN that is configured with IGMP snooping uses default version 2 (unless otherwise configured).
+
+**switch(config-vlan)# ip igmp snooping version **
+
+#### 3.6.2.7 Configure static multicast router(mrouter) port
+This command allows to configure static mrouter ports
+
+**switch(config-vlan)# ip igmp snooping mrouter interface **
+
+#### 3.6.2.6 Configure static multicast group
+A snooping-enabled VLAN cannot forward multicast traffic to ports that do not receive IGMP membership reports. If clients cannot send reports, user can configure a static group which applies to specific ports. The static group allows packets to be forwarded to the static group ports even though they have no client membership reports.
+This command allows users to configure a static multicast group on a VLAN with the receiver port. The interface to the port must be the member of the VLAN.
+
+**switch(config-vlan)# ip igmp snooping static-group interface **
+
+### 3.6.3 Show Commands
+**switch# show ip igmp snooping [[ vlan ] vlan-id ]**
+
+These commands displays IGMP snooping configuration across all the VLANs or the specific VLAN. Configuration details are read from CONFIG_DB entries programmed per VLAN.
+
+ Vlan ID: 10
+ Multicast Router ports: Ethernet8
+ Querier - Disabled
+ IGMP Operation mode: IGMPv2
+ Is Fast-Leave Enabled : Disabled
+ Max Response time = 10
+ Last Member Query Interval = 1000
+ Query interval = 125
+
+
+**switch# show ip igmp snooping groups [[vlan] vlan-id]**
+
+These commands will be used to display L2MC entries from APP_DB.
+
+ Vlan ID : 10
+ -------------
+ 1 (*, 225.0.0.1 ) NumOIF: 1
+ Outgoing Ports: Ethernet4
+ 2 (*, 226.0.0.1 ) NumOIF: 1
+ Outgoing Ports: Ethernet8
+ Total number of entries: 2
+
+
+### 3.6.4 Debug Commands
+Following debug commands will be supported for enabling logging which can be viewed in /var/log/syslog.
+
+ debug igmp-snooping rx/tx
+ debug igmp-snooping vlan
+ debug igmp-snooping group
+ debug igmp-snooping packet
+ debug igmp-snooping errors
+ debug igmp-snooping all
+
+Below show and clear command issues get/clear trigger in l2mcastd DB.
+
+#### debug show igmp-stats vlan
+
+ IGMP packet statistics for vlan10:
+ IGMP Message type Received Sent Errors
+ Membership Query 0 0 0
+ V1 Membership Report 0 0 0
+ V2 Membership Report 4 0 0
+ Group Leave 2 0 0
+ V3 Membership Report 0 0 0
+ PIM hello 0 0 0
+
+ IGMP Error Statistics:
+ Unknown types 0
+ Bad Length 0
+ Bad Checksum 0
+
+ #### debug show igmp-groups
+
+ Total Number of Groups: 2
+ IGMP Connected Group Membership
+ Group Address Interface Uptime Expires Last Reporter
+ 225.0.0.1 vlan10 00:00:42 Never Static
+ Member Ports: Ethernet4,
+ 226.0.0.1 vlan10 00:00:42 00:02:10 10.10.10.1
+ Member Ports: Ethernet8,
+
+#### debug clear igmp-stats vlan
+#### debug clear igmp-groups vlan
+#### debug clear igmp-mcache vlan
+
+
+### 3.6.5 REST API Support
+
+
+
+# 4 Flow Diagrams
+## 4.1 IGMP Snooping Enable on VLAN
+
+
+
+__Figure 2: Enable IGMP Snooping on VLAN__
+
+
+## 4.2 Static L2MC add flow
+
+
+
+__Figure 3: Static L2MC add__
+
+
+
+## 4.3 Dynamic L2MC add flow
+
+
+
+__Figure 4: Dynamic L2MC add__
+
+
+
+## 4.4 Port Down flow
+
+
+
+__Figure 5: Port down flow__
+
+
+
+## 4.5 VLAN member-port delete flow
+
+
+
+__Figure 6: VLAN member-port delete flow__
+
+
+
+## 4.6 STP state change flow
+
+
+
+__Figure 7: STP state change flow__
+
+
+
+# 5 Error Handling
+# 6 Serviceability and Debug
+Debug commands as described in Debug Command section will be supported. Debug command output will be captured as part of tech support.
+- CLI configuration error will be displayed via console and configuration will be rejected
+- Internal processing error within SwSS will be logged in syslog with ERROR level
+- SAI interaction errors will be logged in syslog
+
+# 7 Warm Boot Support
+The traffic corresponding to the active L2MC flows should not be disturbed during the warm reboot process.
+
+- Planned l2mcastd docker warm boot
+ - l2mcastd is responsible for restoring static and dynamic learnt flows from APP_DB and handles l2mc entry change from port state and vlan member port state change events, and pushes updated entry to APP_DB.
+ - Snooping new entries and aging of existing l2mc entries will stop when l2mcastd is away.
+ - If switch is an active querier, l2mcastd sends out query immediatly to check available active memebers.
+- Planned Swss docker warm boot
+ - l2mcOrch is responsible for restoring static and dynamic learnt l2mc entries from APP_DB and cache those entries with OID.
+
+- Planned system warm boot
+ - Snooping new entries and aging of existing l2mc entries will stop when control plane is away.
+ - l2mcastd restores static and dynamic learnt flows from APP_DB.
+ - If switch is an active querier, l2mcastd sends out query immediatly to check available active members.
+ - l2mcOrch restores static and dynamic learnt l2mc entries from APP_DB.
+
+# 8 Scalability
+
+Below L2MC entries scale will be tested to success on an ASIC with 512 L2MC group support,
+###### Table 3: Scaling limits
+|Name | Scaling value |
+|--------------------------|------------------|
+| Number of VLANS | 512 |
+| Number of L2MC entries | 512 |
+
+
+# 9 Unit Test
+## 9.1 CLI Test Cases
+
+ 1. Verify CLI to enable IGMP Snooping on vlan.
+ 2. Verify CLI to enable IGMP Snooping Querier.
+ 3. Verify CLI to enable fast-leave.
+ 4. Verify CLI to configure Query-interval.
+ 5. Verify CLI to configure last-member-query interval.
+ 6. Verify CLI to configure max-response interval.
+ 7. Verify CLI to configure IGMP version 1.
+ 8. Verify CLI to configure IGMP version 2.
+ 9. Verify CLI to configure IGMP version 3.
+ 10. Verify CLI to add static mrouter port.
+ 11. Verify CLI to add static multicast group.
+ 12. Verify CLI to disable IGMP Snooping on vlan.
+ 13. Verify CLI to disable IGMP Snooping Querier.
+ 14. Verify CLI to disable fast-leave.
+ 15. Verify CLI to un-configure Query-interval.
+ 16. Verify CLI to un-configure last-member-query interval.
+ 17. Verify CLI to un-configure max-response interval.
+ 18. Verify CLI to un-configure IGMP version 1.
+ 19. Verify CLI to un-configure IGMP version 2.
+ 20. Verify CLI to un-configure IGMP version 3.
+ 21. Verify CLI to delete static mrouter port.
+ 22. Verify CLI to delete static multicast group.
+ 23. Verify CLI to display IGMP Snooping configured on vlan.
+ 24. Verify CLI to display multicast groups learnt on vlan.
+ 25. Verify CLI to display protocol statistics.
+ 26. Verify CLI to clear protocol statistics.
+ 27. Verify CLI to clear multicast groups learnt.
+ 28. Verify configuration save and verify after reload.
+ 29. Verify unsaved configuration loss after reload.
+
+
+## 9.2 Rest API Test Cases
+
+## 9.3 Functional Test Cases
+
+ 1. Verify IGMP Snooping enable/disable configuration on vlan.
+ 2. Verify IGMP reports/leaves received and processed.
+ 3. Verify General Query messages and Group Specific queries.
+ 4. Verify PIM hello packets are received and processed.
+ 5. Verify IGMP/PIM protocol pkts trap happening fine when switch comes up after the reboot
+ 6. Verify IGMP stats updated for IGMP reports, leaves, and membership queries.
+ 7. Verify static IGMP group addition/deletion through configuration.
+ 8. Verify multicast data forwarding happening using static l2mc entry programmed in hardware.
+ 9. Verify l2mc entry creation when dynamic IGMP report is received.
+ 10. Verify multicast data forwarding happening for the dynamic learnt l2mc entry programmed in hardware.
+ 11. Verify existing l2mc entry updated with new portlist based on the IGMP report from second port.
+ 12. Verify multicast data forwaring is happening for the new member port added.
+ 13. Verify member port removed from l2mc entry based on IGMP leave.
+ 14. Verify multicast data forwarding not happening on the port where leave has processed.
+ 15. Verify dynamic mrouter port added to the l2mc entry member portlist.
+ 16. Verify multicast data forwarding happens to the newly added dynamic mrouter port also.
+ 17. Add static mrouter port and verify multicast data forwarding happens to the newly added static mrouter port also.
+ 18. Verify l2mc entry member port list update at l2mcastd when one of the member port goes down.
+ 19. Verify l2mc entry deletion when last member port goes down.
+ 20. Verify multicast data forwarding happens to the newly updated member ports when vlan member port removal happens.
+ 21. Verify mrouter port timeout.
+ 22. Verify dynamic learnt member port timeout.
+ 23. Verify fast-leave.
+ 24. Verify Queries by modifying Query interval.
+ 25. Verify Last member query interval.
+ 26. Verify max response interval.
+ 27. Verify error messages are logged if l2mcastd gets error writing to APP_DB.
+ 28. Verify error messages are logged if l2mcOrch gets errors when writing to ASIC_DB.
+ 29. Verify error messages are logged if l2mcOrch gets errors when creating l2mc group.
+ 30. Verify error messages are logged if l2mcOrch gets error when creating l2mc memberlist.
+ 31. Verify error messages are logged if l2mcOrch gets error when creating l2mc entry.
+ 32. Verify tracing of l2mcastd at different log levels.
+ 33. Verify tracing of L2mcOrch at different log levels.
+ 34. Execute debug dump commands for dumping the internal operational data/state of L2mcastd and L2mcOrch.
+
+## 9.4 IGMPv1,V2 and V3 cases.
+
+ Verify functional test cases for IGMPv1,V2 and V3.
+
+## 9.5 Warm boot Test Cases
+
+ 1. Verify l2mc docker warm boot. Verify active l2mc traffic flows are not affected during warm boot.
+ 2. Verify Swss docker warm boot. Verify active l2mc traffic flows are not affected during warm boot.
+ 3. Verify system warm boot.
+
+## 9.6 Scaling Test Cases
+
+ 1. Verify with Snooping configured on 512 VLANs.
+ 2. Verify maximum of 512 L2MC entries.
+
+
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