NVGRE tunnel in SONIC

Table of Content

Revision
Scope
Definitions/Abbreviations
Overview
Requirements
Architecture Design
High-level design
SAI API
CLI/YANG model Enhancements
Warmboot and Fastboot Design Impact
Restrictions Limitations
Testing Requirements Design
Open/Action items

Revision

Rev	Date	Author	Change Description
1.0	09/2021	Vadym Hlushko	Phase 1 Design

Scope

This document provides general information about the NVGRE tunnel feature implementation in SONiC.

Definitions/Abbreviations

Abbreviation	Definition
SONiC	Software for Open Networking in Cloud
NVGRE	Network Virtualization using Generic Routing Encapsulation
VxLAN	Virtual Extensible LAN
VSID	Virtual Subnet Identifier
DB	Database
API	Application Programming Interface
SAI	Switch Abstraction Interface
YANG	Yet Another Next Generation
CLI	Command-line interface

Overview

NVGRE is a network virtualization method that uses encapsulation and tunneling to create large numbers of virtual LANs (VLANs) for subnets that can extend across dispersed data centers and layer 2 (the data link layer) and layer 3 (the network layer). The SONIC has no support of NVGRE tunnel feature and appropriate SAI implementation for it.

From the architecture point of view the new orchagent daemon will be added to cover the NVGRE functionality. New daemon should handle the configuration taken from config DB, and call an appropriate SAI API, which will create tunnel and tunnel maps.

Requirements

This section describes the SONiC requirements for NVGRE feature.

At a high level the following should be supported:

User should be able to create NVGRE tunnel (L2 over L3 tunnel)
User should be able to create VLAN to VSID mapper entries for the NVGRE tunnel
Both VLAN and Bridge to VSID mappers should be supported by the NVGRE tunnel
Only the decapsulation mappers supported
YANG model should be created in order to auto-generate CLI by using the SONiC CLI Auto-generation tool.
CLI for NVGRE tunnel

Counters for NVGRE Tunnel are out of scope of this design document.

Architecture Design

The new tables will be added to Config DB. Unless otherwise stated, the attributes are mandatory.

NVGRE configDB table

NVGRE_TUNNEL|{{tunnel_name}} 
    "src_ip": {{ip_address}} 

NVGRE_TUNNEL_MAP|{{tunnel_name}}|{{tunnel_map_name}}
    "vsid": {{vsid_id}}
    "vlan": {{vlan_id}}

ConfigDB schemas

; Defines schema for NVGRE Tunnel configuration attributes
key                                   = NVGRE_TUNNEL|tunnel_name      ; NVGRE tunnel configuration
; field                               = value
src_ip                                = ipv4 or ipv6                  ; IP source address

;value annotations
h16        = 1*4HEXDIG
ls32       = h16 ":" h16
dec-octet  = DIGIT                     ; 0-9
             / %x31-39 DIGIT           ; 10-99
             / "1" 2DIGIT              ; 100-199
             / "2" %x30-34 DIGIT       ; 200-249
ipv4       = dec-octet "." dec-octet "." dec-octet "." dec-octet
ipv6       = 6( h16 ":" ) ls32
             /                       "::" 5( h16 ":" ) ls32
             / [               h16 ] "::" 4( h16 ":" ) ls32
             / [ *1( h16 ":" ) h16 ] "::" 3( h16 ":" ) ls32
             / [ *2( h16 ":" ) h16 ] "::" 2( h16 ":" ) ls32
             / [ *3( h16 ":" ) h16 ] "::"    h16 ":"   ls32
             / [ *4( h16 ":" ) h16 ] "::"              ls32
             / [ *5( h16 ":" ) h16 ] "::"              h16
             / [ *6( h16 ":" ) h16 ] "::"

; Defines schema for NVGRE Tunnel map configuration attributes
key                                   = NVGRE_TUNNEL|tunnel_name|tunnel_map_name ; NVGRE tunnel configuration
; field                               = value
vsid                                  = DIGITS                             ; 1 to 16 million values
vlan                                  = 1\*4DIGIT                          ; 1 to 4094 Vlan id

Orchestration agent

The following orchestration agents will be added or modified. The flow diagrams are captured in a later section.

Figure 1. Orchestration agents

NvgreOrch

nvgreorch - it is an orchestration agent that handles the configuration requests directly from ConfigDB. The nvgreorch is responsible for creating the tunnel and attaches encap and decap mappers. Both VLAN and Bridge tunnel maps are created for NVGRE tunnel by default, so it would be possible to apply both VLAN/VSID and Bridge/VSID map entries.

Orchdaemon

orchdaemon - it is the main orchestration agent, which handles all Redis DB's updates, then calls appropriate orchagent, the new nvgreorch should be registered inside an orchdaemon.

High-Level Design

The following sub-modules will be modified:

sonic-swss - will be extended with the new orchestration agent for NVGRE.
sonic-swss-common - will be extended with the new tables for ConfigDB.
sonic-utilities - will be extened with the new CLI.

Sequence diagrams

Figure 2. NVGRE Tunnel creation flow

Figure 3. NVGRE Tunnel Map creation flow

Figure 4. NVGRE Tunnel delete flow

Note that deleting a tunnel requires the user to remove all the configuration that are associated with this tunnel, it will not be done for the user automatically.

Figure 5. NVGRE Tunnel Map delete flow

Figure 6. NVGRE Tunnel CLI config

Figure 7. NVGRE Tunnel CLI show

SAI API

The NVGRE Tunnel feature require at least SAI 1.9 or above.

NVGRE component	SAI attribute
NVGRE tunnel type	SAI_TUNNEL_TYPE_NVGRE
Decap mapper	SAI_TUNNEL_MAP_TYPE_VSID_TO_VLAN_ID
Decap mapper	SAI_TUNNEL_MAP_TYPE_VSID_TO_BRIDGE_IF
NVGRE tunnel termination entry type	SAI_TUNNEL_TERM_TABLE_ENTRY_TYPE_P2MP

CLI/YANG model Enhancements

NVGRE Tunnel YANG model

module sonic-nvgre-tunnel {

    yang-version 1.1;

    namespace "http://github.com/Azure/sonic-nvgre-tunnel";
    prefix nvgre;

    import ietf-inet-types {
        prefix inet;
    }

    import sonic-vlan {
        prefix vlan;
    }

    description "NVGRE Tunnel YANG Module for SONiC OS";

    revision 2021-10-31 {
        description
            "First Revision";
    }

    container sonic-nvgre-tunnel {

        container NVGRE_TUNNEL {

            description "NVGRE_TUNNEL part of config_db.json";

            list NVGRE_TUNNEL_LIST {

                key "tunnel_name";

                leaf tunnel_name {
                    description "NVGRE Tunnel name";

                    type string {
                        length 1..255;
                    }
                }

                leaf src_ip {
                    description "Source IP address";

                    mandatory true;
                    type inet:ip-address;
                }

            }
            /* end of NVGRE_TUNNEL_LIST */

        }
        /* end of container NVGRE_TUNNEL */

        container NVGRE_TUNNEL_MAP {

            description "NVGRE_TUNNEL_MAP part of config_db.json";

            list NVGRE_TUNNEL_MAP_LIST {

                key "tunnel_name tunnel_map_name";

                leaf tunnel_name {
                    description "NVGRE Tunnel name";

                    type leafref {
                        path /nvgre:sonic-nvgre-tunnel/nvgre:NVGRE_TUNNEL/nvgre:NVGRE_TUNNEL_LIST/nvgre:tunnel_name;
                    }
                }

                leaf tunnel_map_name {
                    description "NVGRE Tunnel map name";

                    type string {
                        length 1..255;
                    }
                }

                leaf vlan_id {
                    description "VLAN identifier";

                    mandatory true;
                    type uint16 {
                        range 1..4094;
                    }
                }

                leaf vsid {
                    description "Virtual Subnet Identifier";

                    mandatory true;
                    type uint32 {
                        range 0..16777214;
                    }
                }

            }
            /* end of NVGRE_TUNNEL_MAP_LIST */

        }
        /* end of container NVGRE_TUNNEL_MAP */

    }
    /* end of container sonic-nvgre-tunnel */

}
/* end of module sonic-nvgre-tunnel */

CLI tree

Commands summary (Phase #2):

	- config nvgre-tunnel add/del <nvgre_tunnel_name> --src-ip <src_ip>
	- config nvgre-tunnel-map add/del <nvgre_tunnel_name> <tunnel_map_name> --vlan_id <vlan_id> --vsid <vsid_id>
	- show nvgre-tunnel
	- show nvgre-tunnel-map

Show CLI command

Show command should be extended in order to add "nvgre-tunnel" and "nvgre-tunnel-map" aliases:

admin@sonic:~$ show nvgre-tunnel
TUNNEL NAME    SRC IP
-------------  --------
tunnel1        10.0.0.1
tunnel2        2.2.2.2
tunnel3        3.3.3.3

=============================================

admin@sonic:~$ show nvgre-tunnel-map
TUNNEL NAME    TUNNEL MAP NAME    VLAN ID    VSID
-------------  -----------------  ---------  ------
tunnel_1       Vlan1000           1000       5000

Config CLI command

Config command should be extended in order to add "nvgre-tunnel" and "nvgre-tunnel-map" aliases:

admin@sonic:~$ config nvgre-tunnel --help
Usage: nvgre-tunnel [OPTIONS] COMMAND [ARGS]...

  NVGRE_TUNNEL part of config_db.json

Options:
  --help  Show this message and exit.

Commands:
  add     Add object in NVGRE_TUNNEL.
  delete  Delete object in NVGRE_TUNNEL.

=============================================

admin@sonic:~$ config nvgre-tunnel add --help
Usage: add [OPTIONS] TUNNEL_NAME

  Add object in NVGRE_TUNNEL.

Options:
  --src-ip  Source IP address[mandatory]
  --help    Show this message and exit.

=============================================

admin@sonic:~$ config nvgre-tunnel-map --help
Usage: nvgre-tunnel-map [OPTIONS] COMMAND [ARGS]...

  NVGRE_TUNNEL_MAP part of config_db.json

Options:
  --help  Show this message and exit.

Commands:
  add     Add object in NVGRE_TUNNEL_MAP.
  delete  Delete object in NVGRE_TUNNEL_MAP.

=============================================

admin@sonic:~$ config nvgre-tunnel-map add --help
Usage: add [OPTIONS] TUNNEL_NAME TUNNEL_MAP_NAME

  Add object in NVGRE_TUNNEL_MAP.

Options:
  --vlan-id  VLAN identifier[mandatory]
  --vsid     Virtual Subnet Identifier[mandatory]
  --help     Show this message and exit.

Config DB Enhancements

The ConfigDB will be extended with next objects:

{
	"NVGRE_TUNNEL": {
		"tunnel1": {
			"src_ip": "2.2.2.2"
		}
	},
	"NVGRE_TUNNEL_MAP": {
		"tunnel1|Vlan2000": {
			"vlan_id": "2000",
			"vsid": "2000",
		}
	}
}

Warmboot and Fastboot Design Impact

No impact on Warmboot and Fastboot features.

Restrictions/Limitations

The number of the tunnels are not limited by SONiC, but if ASIC vendor reach the max resources, the SAI will return an error, when the user will try to create a new tunnel or tunnel map and orchagent will abort.

Testing Requirements/Design

The tests will be implemented under the VS environment and will be placed - sonic-swss/tests sub-module.

Unit Test cases

VS test cases:

create NVGRE Tunnel
- create a tunnel with invalid source IP address
- create a tunnel with valid params
remove NVGRE Tunnel
- remove existing tunnel
- remove unexisting tunnel
- remove a tunel with which have associated with a tunel maps
create NVGRE Tunnel Map
- create a tunnel map with invalid VLAN identifier
- create a tunnel map with invalid VSID number
- create a tunnel map with unexisting NVGRE Tunnel name
- create valid tunnel map
remove NVGRE Tunnel Map
- remove existing tunnel
- remove unexisting tunnel

System Test cases

NVGRE decap:

apply NVGRE config
send encapsulated traffic
validate if decapsulation processed correctly

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nvgre_tunnel.md

nvgre_tunnel.md

NVGRE tunnel in SONIC

Table of Content

Revision

Scope

Definitions/Abbreviations

Overview

Requirements

Architecture Design

NVGRE configDB table

ConfigDB schemas

Orchestration agent

Figure 1. Orchestration agents

NvgreOrch

Orchdaemon

High-Level Design

Sequence diagrams

Figure 2. NVGRE Tunnel creation flow

Figure 3. NVGRE Tunnel Map creation flow

Figure 4. NVGRE Tunnel delete flow

Figure 5. NVGRE Tunnel Map delete flow

Figure 6. NVGRE Tunnel CLI config

Figure 7. NVGRE Tunnel CLI show

SAI API

CLI/YANG model Enhancements

NVGRE Tunnel YANG model

CLI tree

Show CLI command

Config CLI command

Config DB Enhancements

Warmboot and Fastboot Design Impact

Restrictions/Limitations

Testing Requirements/Design

Unit Test cases

System Test cases

Open/Action items

Files

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History

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NVGRE tunnel in SONIC

Table of Content

Revision

Scope

Definitions/Abbreviations

Overview

Requirements

Architecture Design

NVGRE configDB table

ConfigDB schemas

Orchestration agent

Figure 1. Orchestration agents

NvgreOrch

Orchdaemon

High-Level Design

Sequence diagrams

Figure 2. NVGRE Tunnel creation flow

Figure 3. NVGRE Tunnel Map creation flow

Figure 4. NVGRE Tunnel delete flow

Figure 5. NVGRE Tunnel Map delete flow

Figure 6. NVGRE Tunnel CLI config

Figure 7. NVGRE Tunnel CLI show

SAI API

CLI/YANG model Enhancements

NVGRE Tunnel YANG model

CLI tree

Show CLI command

Config CLI command

Config DB Enhancements

Warmboot and Fastboot Design Impact

Restrictions/Limitations

Testing Requirements/Design

Unit Test cases

System Test cases

Open/Action items