IPv6 traffic impacted after upgrade to NSX-T 3.1 from NSX-T 3.0.1 and 3.0.2

Products

• VMware NSX Networking

Issue/Introduction

Symptoms:

• IPv6 forwarding is disabled in data path after upgrade
• connectivity loss for IPv6 traffic

Environment

VMware NSX-T Data Center
VMware NSX-T Data Center 3.x

Cause

This issue occurs because of a Policy engine change as of VMware NSX-T Data Center 3.1 which affects the L3 forwarding mode when IPv6 traffic is utilized.

Resolution

This is a known issue affecting VMware NSX-T Data Center 3.1.0.

This issue is resolved in VMware NSX-T Data Center 3.1.1.

Workaround:

Prior to upgrade from VMware NSX-T Data Center 3.0.1/3.0.2 to VMware NSX-T Data Center 3.1.0, make sure the L3 forwarding mode value on Policy and MP is the same. 

If they are different, update the mode on Policy using UI or Policy API. 

Workaround:

1. From your browser, log in with admin privileges to an NSX Manager at https://<nsx-manager-ip-address>.
2. Select Networking > Networking Settings.
3. Click the Global Networking Config tab.
4. Edit the Global Gateway Configuration and select IPv4 and IPv6 for the L3 Forwarding Mode. Only IPv6 is not supported. 
5. Click Save.

API Example:

PATCH https://<policy-ip>/policy/api/v1/infra/global-config
{
    "fips": {
        "lb_fips_enabled": false
    },
    "l3_forwarding_mode": "IPV4_AND_IPV6",
    "uplink_mtu_threshold": 9200,
    "vdr_mac": "02:50:56:56:44:52",
    "vdr_mac_nested": "02:50:56:56:44:53",
    "allow_changing_vdr_mac_in_use": false,
    "arp_limit_per_gateway": 50000,
    "resource_type": "GlobalConfig",
    "id": "global-config",
    "display_name": "default",
    "path": "/infra/global-config",
    "relative_path": "global-config",
    "parent_path": "/infra",
    "unique_id": "6ad09314-ea39-4fd3-bef9-cbf124c3e43d",
    "marked_for_delete": false,
    "overridden": false,
    "_create_time": 1599172410181,
    "_last_modified_user": "admin",
    "_last_modified_time": 1599175772818,
    "_system_owned": true,
    "_create_user": "system",
    "_protection": "NOT_PROTECTED",
    "_revision": 1
}

See the NSX-T Product Documentation for more details.

Additional Information

Impact/Risks:
This issue affects upgrades from NSX-T Data Center 3.0.1 and 3.0.2 to 3.1.

This does not affect upgrades from NSX-T Data Center 3.0.0 to 3.1.
This does not affect upgrades from NSX-T Data Center 2.5.x to 3.1.