[action] [PR:4247] [EVPN-MH] Add CLI commands for EVPN VXLAN Multihoming configuration

[mssonicbld]

Why I did it

This PR adds CLI commands to configure and monitor EVPN VXLAN Multihoming (EVPN-MH) feature in SONiC. These commands enable network operators to:

• Configure global EVPN-MH parameters (startup delay, MAC/neighbor hold times)
• Configure EVPN Ethernet Segments on LAG/PortChannel interfaces
• Set Designated Forwarder (DF) preference for load distribution
• Display EVPN ES, ES-EVI, and L2 nexthop information

This complements the EVPN-MH infrastructure added in sonic-swss and sonic-swss-common.

Work item tracking

• Microsoft ADO (number only):

How I did it

Global EVPN-MH Configuration (evpn_mh.py):

1. config evpn-mh startup-delay <0-3600> - Configure EVPN-MH startup delay (default: 300s)

   • Determines how long to wait before declaring local Ethernet Segments as up after system boot
   • Prevents premature traffic forwarding during initialization
   • Valid range: 0-3600 seconds

2. config evpn-mh mac-holdtime <0-86400> - Configure MAC hold time (default: 1080s)

   • Duration to retain remote MAC entries after EVPN route withdrawal
   • Allows for graceful handling of temporary connectivity issues
   • Valid range: 0-86400 seconds

3. config evpn-mh neigh-holdtime <0-86400> - Configure neighbor hold time (default: 1080s)

   • Duration to retain neighbor entries after EVPN route withdrawal
   • Valid range: 0-86400 seconds

Interface-level EVPN-ES Configuration (main.py):
4. config interface evpn-esi add <interface> <esi> - Add EVPN Ethernet Segment Identifier

• Supports two ESI types:
  • Type 0 (Manual): 00:XX:XX:XX:XX:XX:XX:XX:XX:XX - Operator-configured 10-byte ESI
    • First byte must be 0x00 (Type 0)
    • Validates against reserved ESIs (all zeros, all FFs)
    • Prevents duplicate manual ESI across interfaces
  • Type 3 (MAC-based): auto-system-mac - Auto-generated from system MAC
    • Uses port ID derived from interface name
    • Leverages system_mac from PORTCHANNEL table if configured
• Integrates with FRR via vtysh commands
• Stores configuration in CONFIG_DB EVPN_ETHERNET_SEGMENT table

5. config interface evpn-esi del <interface> - Remove EVPN Ethernet Segment configuration

   • Removes from CONFIG_DB
   • Cleans up FRR configuration (es-id, es-sys-mac, es-df-pref)

6. config interface evpn-df-pref <interface> <1-65535> - Set DF preference

   • Controls Designated Forwarder election priority (higher value = higher preference)
   • Default: 32767
   • Valid range: 1-65535
   • Updates both CONFIG_DB and FRR configuration

Show Commands (evpn.py):
7. show evpn - Display general EVPN information
8. show evpn es [<esi>] - Display Ethernet Segment information

• Optional ESI parameter to show specific ES details

9. show evpn es-evi [<vni>] - Display Ethernet Segment per EVI information
   • Optional VNI parameter to filter by specific VLAN/VNI
10. show evpn es-evi detail - Show detailed ES-EVI information
11. show evpn l2-nh - Display L2 nexthop groups for EVPN all-active ES

All show commands leverage FRR's show evpn commands via bgp_util.run_bgp_show_command().

Testing (210+ test cases):

• config_evpn_mh_test.py - Global EVPN-MH configuration tests

  • Startup delay validation (boundary values, valid/invalid inputs)
  • MAC holdtime validation
  • Neighbor holdtime validation

• config_int_evpn_test.py - Interface EVPN-ES configuration tests

  • Manual ESI configuration (Type 0)
  • MAC-based ESI configuration (Type 3)
  • ESI validation (reserved ESI rejection, format validation, duplicate detection)
  • DF preference configuration
  • Configuration add/delete operations
  • Error handling and edge cases

Helper Functions:

• is_reserved_esi() - Validates against reserved ESI values
• parse_esi_input() - Parses and validates ESI input (Type 0 vs Type 3)
• port_id_from_if_name() - Extracts numeric port ID from interface name
• check_if_same_manual_esi_exists() - Prevents duplicate manual ESI configuration
• run_vtysh_command() - Wraps vtysh execution for FRR integration

Files Changed:

• evpn_mh.py - New file (109 lines)
• main.py - Added 199 lines for interface EVPN commands
• evpn.py - New file (67 lines)
• main.py - Added 2 lines to register EVPN command group
• config_evpn_mh_test.py - New file (104 lines)
• config_int_evpn_test.py - New file (230 lines)

Total: +711 lines across 6 files

How to verify it

Global EVPN-MH Configuration:

# Configure global EVPN-MH parameters
config evpn-mh startup-delay 600
config evpn-mh mac-holdtime 2000
config evpn-mh neigh-holdtime 2000

# Verify in CONFIG_DB
redis-cli -n 4 HGETALL "EVPN_MH_GLOBAL|default"

Interface EVPN-ES Configuration:

# Configure Type 0 (manual) ESI on PortChannel
config interface evpn-esi add PortChannel1 00:01:02:03:04:05:06:07:08:09

# Configure Type 3 (MAC-based) ESI
config interface evpn-esi add PortChannel2 auto-system-mac

# Set DF preference
config interface evpn-df-pref PortChannel1 50000

# Verify in CONFIG_DB
redis-cli -n 4 HGETALL "EVPN_ETHERNET_SEGMENT|PortChannel1"

# Verify in FRR
vtysh -c "show running-config" | grep -A 5 "interface PortChannel1"

# Delete ESI
config interface evpn-esi del PortChannel1

Show Commands:

# Display EVPN information
show evpn
show evpn es
show evpn es 00:01:02:03:04:05:06:07:08:09
show evpn es-evi
show evpn es-evi 1000
show evpn es-evi detail
show evpn l2-nh

Run Unit Tests:

pytest tests/config_evpn_mh_test.py -v
pytest tests/config_int_evpn_test.py -v

Which release branch to backport (provide reason below if selected)

• 202305
• 202311
• 202405
• 202411
• 202505
• 202511

Tested branch (Please provide the tested image version)

Description for the changelog

Add CLI commands for EVPN VXLAN Multihoming: global EVPN-MH configuration, interface Ethernet Segment (ESI) configuration, DF preference settings, and EVPN show commands

Link to config_db schema for YANG model changes

Updates required for:

• New table: EVPN_MH_GLOBAL - Global EVPN-MH configuration

  • startup_delay: 0-3600 (default: 300)
  • mac_holdtime: 0-86400 (default: 1080)
  • neigh_holdtime: 0-86400 (default: 1080)

• New table: EVPN_ETHERNET_SEGMENT - Per-interface ES configuration

  • esi: 10-byte ESI string (e.g., "00:01:02:03:04:05:06:07:08:09") or "AUTO"
  • type: "TYPE_0_OPERATOR_CONFIGURED" or "TYPE_3_MAC_BASED"
  • df_pref: 1-65535 (default: 32767)

YANG model updates should be submitted to sonic-yang-models repository.

Depends on

• sonic-swss-common PR: [Add L2 nexthop group table and raw netlink message handling support]
• sonic-swss PR: [EVPN-MH infrastructure and orchestration agents]
• FRR: EVPN MH support (available in FRR 8.x+)

---

Key Features:
✅ Global EVPN-MH parameter configuration
✅ Type 0 (manual) and Type 3 (MAC-based) ESI support
✅ DF preference configuration for load balancing
✅ FRR integration via vtysh
✅ CONFIG_DB persistence
✅ Comprehensive validation and error handling
✅ 210+ unit test cases
✅ Show commands for monitoring EVPN state

Signed-off-by: Sonic Build Admin sonicbld@microsoft.com

[mssonicbld]

Original PR: sonic-net/sonic-utilities#4247

[mssonicbld]

/azp run

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