The 10.2 release of VMware Cloud Director from networking perspective was a massive one. NSX-V vs NSX-T gap was closed and in some cases NSX-T backed Org VDCs now provide more networking functionality than the NSX-V backed ones. UI has been redesigned with new dedicated Networking sections however some new features are currently available only in API.
Let me dive straight in so you do not miss any.
NSX-T Advanced Load Balancing (Avi) support
This is a big feature that requires its own blog post. Please read here. In short, NSX-T backed Org VDCs can now consume network load balancer services that are provided by the new NSX-T ALB / Avi.
Distributed Firewall and Data Center Groups
Another big feature combines Cross VDC networking, shared networks and distributed firewall (DFW) functionality. The service provider first must create Compute Provider Scope. This is basically a tag – abstraction of compute fault domains / availability zones and is done either at vCenter Server level or at Provider VDC level.
The same can be done for each NSX-T Manager where you would define Network Provider Scope.
Once that is done, the provider can create Data Center Group(s) for a particular tenant. This is done from the new networking UI in the Tenant portal by selecting one or multiple Org VDCs. The Data Center Group will now become a routing domain with networks spanning all Org VDCs that are part of the group, with a single egress point (Org VDC Gateway) and the distributed firewall.
Routed networks will automatically be added to a Data Center Group if they are connected to the group Org VDC Edge Gateway. Isolated networks must be added explicitly. An Org VDC can be member of multiple Data Center Groups.
If you want the tenant to use DFW, it must be explicitly enabled and the tenant Organization has to have the correct rights. The DFW supports IP Sets and Security Groups containing network objects that apply rules to all connected VMs.
Note that only one Org VDC Edge Gateway can be added to the Data Center Group. This is due to the limitation that NSX-T logical segment can be attached and routed only via single Tier-1 GW. The Tier-1 GW is in active / standby mode and can theoretically span multiple sites, but only single instance is active at a time (no multi-egress).
VRF-Lite Support
VRF-Lite is an object that allows slicing single NSX-T Tier-0 GW into up to 100 independent virtual routing instances. Lite means that while these instances are very similar to the real Tier-0 GW they do support only subset of its features: routing, firewalling and NATing.
In VCD, when tenant requires direct connectivity to on-prem WAN/MPLS with fully routed networks (instead of just NAT-routed ones), in the past the provider had to dedicated a whole external network backed by Tier-0 GW to such tenant. Now the same can be achieved with VRF which greatly enhances scalability of the feature.
There are some limitations:
- VRF inherits its parent Tier-0 deployment mode (HA A/A vs A/S, Edge Cluster), BGP local ASN and graceful restart setting
- all VRFs will share its parent uplinks physical bandwidth
- VRF uplinks and peering with upstream routers must be individually configured by utilizing VLANs from a VLAN trunk or unique Geneve segments (if upstream router is another Tier-0)
- an an alternative to the previous point EVPN can be used which allows single MP BGP session for all VRFs and upstream routers with data plane VXLAN encapsulation. Upstream routers obviously must support EVPN.
- the provider can import into VCD as an external network either the parent Tier-0 GW or its child VRFs, but not both (mixed mode)
IPv6
VMware Cloud Director now supports dual stack IPv4/IPv6 (both for NSX-V and NSX-T backed networks). This must be currently enabled via API version 35 either during network creation or via PUT on the OpenAPI network object by specifying:
“enableDualSubnetNetwork”: true
In the same payload you also have to add the 2nd subnet definition.
PUT https://{{host}}/cloudapi/1.0.0/orgVdcNetworks/urn:vcloud:network:c02e0c68-104c-424b-ba20-e6e37c6e1f73
...
"subnets": {
"values": [
{
"gateway": "172.16.100.1",
"prefixLength": 24,
"dnsSuffix": "fojta.com",
"dnsServer1": "10.0.2.210",
"dnsServer2": "10.0.2.209",
"ipRanges": {
"values": [
{
"startAddress": "172.16.100.2",
"endAddress": "172.16.100.99"
}
]
},
"enabled": true,
"totalIpCount": 98,
"usedIpCount": 1
},
{
"gateway": "fd13:5905:f858:e502::1",
"prefixLength": 64,
"dnsSuffix": "",
"dnsServer1": "",
"dnsServer2": "",
"ipRanges": {
"values": [
{
"startAddress": "fd13:5905:f858:e502::2",
"endAddress": "fd13:5905:f858:e502::ff"
}
]
},
"enabled": true,
"totalIpCount": 255,
"usedIpCount": 0
}
]
}
...
"enableDualSubnetNetwork": true,
"status": "REALIZED",
...
The UI will still show only the primary subnet and IP address. The allocation of the secondary IP to VM must be either done from its guest OS or via automated network assignment (DHCP, DHCPv6 or SLAAC). DHCPv6 and SLAAC is only available for NSX-T backed Org VDC networks but for NSX-V backed networks you could use IPv6 as primary subnet (with IPv6 pool) and IPv4 with DHCP addressing as the secondary.
PUT https://{{host}}/cloudapi/1.0.0/edgeGateways/urn:vcloud:gateway:5234d305-72d4-490b-ab53-02f752c8df70/slaacProfile
{
"enabled": true,
"mode": "SLAAC",
"dnsConfig": {
"domainNames": [],
"dnsServerIpv6Addresses": [
"2001:4860:4860::8888",
"2001:4860:4860::8844"
]
}
}
And here is the corresponding view from NSX-T Manager:
And finally a view on deployed VM’s networking stack:
DHCP
Speaking of DHCP, NSX-T supports two modes. Network mode (where DHCP service is attached directly to a network and needs an IP from that network) and Edge mode where the DHCP service runs on Tier-1 GW loopback address. VCD now supports both modes (via API only). The DHCP Network mode will work for isolated networks and is portable with the network (meaning the network can be attached or disconnected from the Org VDC Edge GW) without DHCP service disruption. However, before you can deploy DHCP service in Network mode you need to specify Services Edge Cluster (for Edge mode that is not needed as the service runs on the Tier-1 Edge GW). The cluster definition is done via Network Profile at Org VDC level.
In order to use DHCPv6 the network must be configured in Network mode and attached to Org VDC Edge GW with SLAAC profile configured with DHCPv6 mode.
Other Features
- vSphere Distributed Switch support for NSX-T segments (also known as Converged VDS), although this feature was already available in VCD 10.1.1+
- NSX-T IPSec VPN support in UI
- NSX-T L2VPN support, API only
- port group backed external networks (used for NSX-V backed Org VDCs) can now have multiple port groups from the same vCenter Server instance (useful if you have vDS per cluster for example)
- /31 external network subnets are supported
- Org VDC Edge GW object now supports metadata
NSX-V vs NSX-T Feature Parity
Let me conclude with an updated chart showing comparison of NSX-V vs NSX-T features in VMware Cloud Director 10.2. I highlighted new additions in green.
You start by deploying Avi controller cluster (highly available 3 nodes) which integrates with vSphere (to use for compute/storage) and NSX-T (for routing LB data and control plane traffic). The controllers would sit somewhere in your management infrastructure next to all other management solutions.
Avi Service Engines (SE) are VM resources to perform the load balancing. They are similar to NSX-T Edge Nodes in a sense that the load balancing virtual services can be placed on any SE node based on capacity or reservations (as Tier-1 GW can be placed on any Edge Node). Per se there is no strict relationship between tenant’s LB and SE node. SE node can be shared across Org VDC Edge GWs or even tenants. SE node is a VM with up to 10 network interfaces (NICs). One NIC is always needed for the management/control traffic (blue network). The rest (9) are used to connect to the Org VDC Edge GW (Tier-1 GW) via a Service Network logical segment (yellow and orange). The service networks are created by VCD when you enable load balancing service on the Org VDC Edge GW together with DHCP service to provide IP addresses for the attached SEs. It will by default get 10.255.255.0/25 subnet, but the system admin can change it, if it clashes with existing Org VDC networks. Service Engines run each service interface in a different VRF context so there is no worry about IP conflicts or even cross tenant communication.
