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VPCs and Namespaces

VPC

Virtual Private Cloud, similar to the public cloud VPC it provides an isolated private network for the resources with support for multiple subnets each with user-provided VLANs and on-demand DHCP.

apiVersion: vpc.githedgehog.com/v1alpha2
kind: VPC
metadata:
  name: vpc-1
  namespace: default
spec:
  ipv4Namespace: default # Limits to which subnets could be used by VPC to guarantee non-overlapping IPv4 ranges
  vlanNamespace: default # Limits to which switches VPC could be attached to guarantee non-overlapping VLANs
  subnets:
    defaultIsolated: true # Sets default behavior for the current VPC subnets to be isolated
    defaultRestricted: true # Sets default behavior for the current VPC subnets to be restricted
    default: # Each subnet is named, "default" subnet isn't required, but actively used by CLI
      dhcp:
        enable: true # On-demand DHCP server
        range: # Optionally, start/end range could be specified
          start: 10.10.1.10
          end: 10.10.1.99
          pxeURL: tftp://10.10.10.99/bootfilename # PXEURL (optional) to identify the pxe server to use to boot hosts, http query strings are not supported
      subnet: 10.10.1.0/24 # User-defined subnet from ipv4 namespace
      vlan: "1001" # User-defined VLAN from vlan namespace
      isolated: true # Makes subnet isolated from other subnets within the VPC (doesn't affect VPC peering)
      restricted: true # Makes all hosts in the subnet to be isolated from each other
    thrird-party-dhcp: # Another subnet
      dhcp:
        relay: 10.99.0.100/24 # Use third-party DHCP server (DHCP relay configuration), access to it could be enabled using StaticExternal connection
      subnet: "10.10.2.0/24"
      vlan: "1002"
    another-subnet: # Minimal configuration is just a name, subnet and VLAN
      subnet: 10.10.100.0/24
      vlan: "1100"
  permit: # Defines which VPCs could communicate to each other, applied on top of subnets "isolated" flag (doesn't affect VPC peering)
    - [subnet-1, subnet-2, subnet-3] # 1, 2 and 3 subnets could communicate to each other
    - [subnet-4, subnet-5] # Possible to define multiple lists

Isolated and restricted subnets, permit lists

Subnets could be isolated and restricted with ability to define permit lists to allow communication between specific isolated subnets. The permit list is applied on top of the isolated flag and doesn't affect VPC peering.

Isolated subnet means that the subnet has no connectivity with other subnets within the VPC, but it could still be allowed by permit lists.

Restricted subnet means that all hosts in the subnet are isolated from each other within the subnet.

Permit lists are defined as a list of subnets that could communicate to each other.

Third-party DHCP server

In case if you're using thirt-party DHCP server by configuring spec.subnets.<subnet>.dhcp.relay additional information will be added to the DHCP packet it forwards to the DHCP server to make it possible to identify the VPC and subnet. The information is added under the RelayAgentInfo option(82) on the DHCP packet. The relay sets two suboptions in the packet

  • VirtualSubnetSelection -- (suboption 151) is populated with the VRF which uniquely idenitifies a VPC on the Hedgehog Fabric and will be in VrfV<VPC-name> format, e.g. VrfVvpc-1 for VPC named vpc-1 in the Fabric API
  • CircuitID -- (suboption 1) identifies the VLAN which together with VRF (VPC) name maps to a specific VPC subnet

VPCAttachment

Represents a specific VPC subnet assignment to the Connection object which means exact server port to a VPC binding. It basically leads to the VPC being available on the specific server port(s) on a subnet VLAN.

VPC could be attached to a switch which is a part of the VLAN namespace used by the VPC.

apiVersion: vpc.githedgehog.com/v1alpha2
kind: VPCAttachment
metadata:
  name: vpc-1-server-1--mclag--s5248-01--s5248-02
  namespace: default
spec:
  connection: server-1--mclag--s5248-01--s5248-02 # Connection name representing the server port(s)
  subnet: vpc-1/default # VPC subnet name
  nativeVLAN: true # Optional, if true the port will be configured as a native VLAN port (untagged)

VPCPeering

It enables VPC to VPC connectivity. There are tw o types of VPC peering:

  • Local - peering is implemented on the same switches where VPCs are attached
  • Remote - peering is implemented on the border/mixed leafs defined by the SwitchGroup object

VPC peering is only possible between VPCs attached to the same IPv4 namespace.

Local VPC peering

apiVersion: vpc.githedgehog.com/v1alpha2
kind: VPCPeering
metadata:
  name: vpc-1--vpc-2
  namespace: default
spec:
  permit: # Defines a pair of VPCs to peer
  - vpc-1: {} # meaning all subnets of two VPCs will be able to communicate to each other
    vpc-2: {} # see "Subnet filtering" for more advanced configuration

Remote VPC peering

apiVersion: vpc.githedgehog.com/v1alpha2
kind: VPCPeering
metadata:
  name: vpc-1--vpc-2
  namespace: default
spec:
  permit:
  - vpc-1: {}
    vpc-2: {}
  remote: border # indicates a switch group to implement the peering on

Subnet filtering

It's possible to specify which specific subnets of the peering VPCs could communicate to each other using the permit field.

```yaml
apiVersion: vpc.githedgehog.com/v1alpha2
kind: VPCPeering
metadata:
  name: vpc-1--vpc-2
  namespace: default
spec:
  permit: # subnet-1 and subnet-2 of vpc-1 could communicate to subnet-3 of vpc-2 as well as subnet-4 of vpc-2 could communicate to subnet-5 and subnet-6 of vpc-2
  - vpc-1:
      subnets: [subnet-1, subnet-2]
    vpc-2:
      subnets: [subnet-3]
  - vpc-1:
      subnets: [subnet-4]
    vpc-2:
      subnets: [subnet-5, subnet-6]

IPv4Namespace

Defines non-overlapping VLAN ranges for attaching servers. Each switch belongs to a list of VLAN namespaces with non-overlapping VLAN ranges.

apiVersion: vpc.githedgehog.com/v1alpha2
kind: IPv4Namespace
metadata:
  name: default
  namespace: default
spec:
  subnets: # List of the subnets that VPCs can pick their subnets from
  - 10.10.0.0/16

VLANNamespace

Defines non-overlapping IPv4 ranges for VPC subnets. Each VPC belongs to a specific IPv4 namespace.

apiVersion: wiring.githedgehog.com/v1alpha2
kind: VLANNamespace
metadata:
  name: default
  namespace: default
spec:
  ranges: # List of VLAN ranges that VPCs can pick their subnet VLANs from
  - from: 1000
    to: 2999
Last update: March 18, 2024
Created: December 22, 2023