BICAN Support Matrix - Shasta Customer Access Networks

Data sheet - Shasta networking - Customer Access Networks

Overview

Customer Access Networks (CANs) provide the interface between HPE Cray EX system networking and the customer site network. CANs are routed networks with broadcast domain separation. CANs provide higher availability and more flexibility in accessing cloud services compared to traditional “bastion hosts”, and are more in line with the cloud-native architecture of CSM.

CANs provide flexible networking at the edge between the site and HPE Cray EX system to do the following:

  • Perform administrative tasks on the system.
  • Run jobs and move job data to and from the system.
  • Access site resources like DNS and LDAP from the system.

Feature access matrix

In CSM 1.2, the notion of the CAN was expanded to meet customer requests for increased flexibility and policy control.

System Resource Traffic to and from System Management Network or CAN High Speed Network CHN Management Network CMN
System Cloud Resources (APIs) Ingress Jobs-related APIs Jobs-related APIs Administrative APIs
Application Node Servers (UAN, re-purposed CN) Ingress Allowed Allowed Not Allowed
Non-Compute Node (NCN) Servers Ingress Not Allowed Not Allowed Allowed
System Access to External/Site (LDAP, DNS) Egress Allowed Allowed Not Allowed

  • Selection of user access for job control and data movement over the Customer Management Network (CMN) or the Customer High Speed Network (CHN) is made during system installation or upgrade.

  • Creation of the Customer Management Network (CMN) during installation or upgrade is mandatory.

Network overview

TDS CAN overview

Internal networks

  • Node Management Network (NMN) - Provides the internal control plane for systems management and jobs control.
  • Hardware Management Network (HMN) - Provides internal access to system baseboard management controllers (BMC/iLO) and other lower-level hardware access.

External and edge networks

  • Customer Management Network (CMN) - Provides customer access from the site to the system for administrators.
  • Customer Access Network (CAN) or Customer High Speed Network (CHN) provide:
    • Customer access from the site to the system for job control and jobs data movement.
    • Access from the system to the site for network services like DNS, LDAP, and so on.

Supported configurations

Option A: CMN + CAN (Management Network only - Layer 2 separation)

CMN plus CAN

Option B: CMN + CHN (Administration over Management Network, User Access over High Speed Network)

CMN plus CHN

Note: During installation, the High Speed Network (HSN) is not configured until relatively late in the process. Installation generally requires site access for deployment artifacts, site DNS, and more. In order to achieve this, the CMN is used during the installation process for system traffic egress until the HSN is available.

Network capabilities

Layer 2

CMN, CAN, and CHN have broadcast boundaries at the edge between the system and the site.

Layer 3

  • Addressing
    • IPv4 supported (default)
    • IPv6 roadmap
  • Routing
    • Static routes (default) exist on the edge router/switches.
    • Dynamic routing (OSPF) is possible at the edge.

Network sizing and requirements

CMN sizing and requirements

CMN IPv4 sizing and requirements

  • Site routable
  • Contiguous (CIDR block)
  • Non-overlapping with internal networks (configurable during installation)
  • Size estimate is the sum of:
    • Number of Non-Compute Nodes (NCNs) of type master, worker, or storage used by the Kubernetes cluster
    • Number of switches on the Management Network
    • Number of administrative API endpoints
    • Several administrative addresses for switch interfaces and routing
    • A /26 block is typically sufficient for systems with less than approximately 4000 nodes

CAN or CHN sizing and requirements

CAN or CHN IPv4 sizing and requirements

  • Site routable
  • Contiguous (CIDR block)
  • Non-overlapping with internal networks (configurable during installation)
  • Size estimate is the sum of:
    • Number of application nodes requiring access from the site (User Access Node (UAN), login nodes, and more)
    • Number of API endpoints
    • Several administrative addresses for switch interfaces and routing
    • CAN or CHN sizing is largely dependent on customer-specific use cases and application node hardware