Network Setup for Exadata Cloud Infrastructure Instances

This topic describes the recommended configuration for the VCN and several related requirements for the Exadata Cloud Infrastructure instance.

Before you set up an Exadata Cloud Infrastructure instance, you must set up a virtual cloud network (VCN) and other Networking service components.

VCN and Subnets

To launch an Exadata Cloud Infrastructure instance, you must have a Virtual Cloud Network and at least two subnets:

To launch an Exadata Cloud Infrastructure instance, you must have a Virtual Cloud Network, at least two subnets and select the type of DNS resolver you will use:

  • A VCN in the region where you want the Exadata Cloud Infrastructure instance
  • At least two subnets in the VCN. The two subnets are:

    • Client subnet
    • Backup subnet
  • Choose which method of DNS name resolution you will use. See Choices for DNS in Your VCN

Note

For Exadata Cloud Infrastructure instances using The New Exadata Cloud Infrastructure Resource Model , networking is configured on the cloud VM cluster resource.

In general, Oracle recommends using regional subnets , which span all availability domains in the region. For more information, see Overview of VCNs and Subnets.

You will create custom route tables route tables for each subnet. You will also create security rulessecurity rules to control traffic to and from the client network and backup network of the Exadata compute nodes (for The Cloud VM Cluster Resource, nodes are called virtual machines). More information follows about those items.

Option 1: Public Client Subnet with Internet Gateway

This option can be useful when doing a proof-of-concept or development work.

You can use this setup in production if you want to use an internet gateway with the VCN, or if you have services that run only on a public network and need access to the database. See the following diagram and description.

Description of network_exa_public_client.png follows

You set up:

Note

Important See this known issue for information about configuring route rules with service gateway as the target on route tables associated with public subnets.

Option 2: Private Subnets

Oracle recommends private subnets for a production system.

Both subnets are private and cannot be reached from the internet. See the following diagram and description.

Description of network_exa_private_client.png follows

You set up:

  • Subnets:

    • Private client subnet.
    • Private backup subnet.
  • Gateways for the VCN:

  • Route tables:

    • Custom route table for the private client subnet, with the following rules:

      • A rule for the on-premises network's CIDR, and target = DRG.
      • A rule for the service CIDR label called All <region> Services in Oracle Services Network, and target = the service gateway. The Oracle Services Network is a conceptual network in Oracle Cloud Infrastructure that is reserved for Oracle services. The rule enables the client subnet to reach the regional Oracle YUM repository for OS updates. Also see Option 2: Service Gateway Access to Both Object Storage and YUM Repos.
      • Optionally, a rule for 0.0.0.0/0, and target = NAT gateway.
    • Separate custom route table for the private backup subnet, with one rule:
      • The same rule as for the client subnet: for the service CIDR label called All <region> Services in Oracle Services Network, and target = the service gateway. This rule enables the backup subnet to reach the regional Object Storage for backups.
  • Security rules to enable the desired traffic to and from the Exadata nodes. See Security Rules for the Exadata Cloud Service instance.
  • Optionally add a Static route on the compute nodes to other OCI services (for VM clusters, the virtual machines) to enable access, if the services are only reachable on the backup subnet and not via. the client subnet, e.g. when using a NAT Gateway.

Requirements for IP Address Space

IP addresses must not overlap, especially when Exadata Cloud Infrastructure instances (and thus VCNs) are in more than one region.

If you're setting up Exadata Cloud Infrastructure instances (and thus VCNs) in more than one region, make sure the IP address space of the VCNs does not overlap. This is important if you want to set up disaster recovery with Oracle Data Guard.

For Exadata X8 and lower, the two subnets you create for the Exadata Cloud Infrastructure instance must not overlap with 192.168.128.0/20.

For Exadata X8M IP addresses (100.64.0.0/10) are used for the interconnect.

The following table lists the minimum required subnet sizes, depending on the Exadata rack size. For the client subnet, each node requires two IP addresses, and in addition, three addresses are reserved for Single Client Access Names (SCANs). For the backup subnet, each node requires one address.

Note

The Networking service reserves three IP addresses in each subnet. Allocating a larger space for the subnet than the minimum required (for example, at least /25 instead of /28) can reduce the relative impact of those reserved addresses on the subnet's available space.

Rack Size Client Subnet: # Required IP Addresses Client Subnet: Minimum Size Backup Subnet: # Required IP Addresses Backup Subnet: Minimum Size
Base System or Quarter Rack (4 addresses * 2 nodes) + 3 for SCANs + 3 reserved in subnet = 14 /28 (16 IP addresses) (3 address * 2 nodes) + 3 reserved in subnet = 9 /28 (16 IP addresses)
Half Rack (4 * 4 nodes) + 3 + 3 = 22 /27 (32 IP addresses) (3 * 4 nodes) + 3 = 15 /28 (16 IP addresses)
Full Rack (4* 8 nodes) + 3 + 3 = 38 /26 (64 IP addresses) (3 * 8 nodes) + 3 = 27 /27 (32 IP addresses)
Flexible infrastructure systems (X8M and higher) 4 addresses per database node (minimum of 2 nodes) + 3 for SCANs + 3 reserved in subnet Minimum size determined by total number of IP addresses needed for database nodes 3 address per database node (minimum of 2 nodes) + 3 reserved in subnet Minimum size determined by total number of IP addresses needed for database nodes

Configuring a Static Route for Accessing the Object Store

All the traffic in an Exadata Cloud Infrastructure instance is, by default, routed through the data network. To route backup traffic to the backup interface (BONDETH1), you need to configure a static route on each of the compute nodes in the cluster. For instructions, see Node Access to Object Storage: Static Route.

Setting Up DNS for an Exadata Cloud Infrastructure Instance

DNS lets you use host names instead of IP addresses to communicate with an Exadata Cloud Infrastructure instance. You can use the Internet and VCN Resolver (the DNS capability built into the VCN) as described in DNS in Your Virtual Cloud Network. Oracle recommends using a VCN Resolver for DNS name resolution for the client subnet. It automatically resolves the Swift endpoints required for backing up databases, patching, and updating the cloud tooling on an Exadata instance.

DNS: Short Names for the VCN, Subnets, and Exadata Cloud Infrastructure instance

For the nodes to communicate, the VCN must use the Internet and VCN Resolver. It enables hostname assignment to the nodes, and DNS resolution of those hostnames by resources in the VCN. It enables round robin resolution of the database's SCANs. It also enables resolution of important service endpoints required for backing up databases, patching, and updating the cloud tooling on an Exadata Cloud Infrastructure instance. The Internet and VCN Resolver is the VCN's default choice for DNS in the VCN. For more information, see DNS in Your Virtual Cloud Network and also DHCP Options.

When you create the VCN, subnets, and Exadata, you must carefully set the following identifiers, which are related to DNS in the VCN:

  • VCN domain label
  • Subnet domain label
  • Hostname prefix for the Exadata Cloud Infrastructure instance's cloud VM cluster or DB system resource

These values make up the node's fully qualified domain name (FQDN):

<hostname_prefix>-######.<subnet_domain_label>.<vcn_domain_label>.oraclevcn.com

For example:

exacs-abcde1.clientpvtad1.acmevcniad.oraclevcn.com

In this example, you assign exacs as the hostname prefix when you create the cloud VM cluster or DB system. The Database service automatically appends a hyphen and a five-letter string with the node number at the end. For example:

  • Node 1: exacs-abcde1.clientpvtad1.acmevcniad.oraclevcn.com
  • Node 2: exacs-abcde2.clientpvtad1.acmevcniad.oraclevcn.com
  • Node 3: exacs-abcde3.clientpvtad1.acmevcniad.oraclevcn.com
  • And so on

Requirements for the hostname prefix:

  • Recommended maximum: 12 characters. For more information, see the example under the following section, "Requirements for the VCN and subnet domain labels".
  • Cannot be the string localhost

Requirements for the VCN and subnet domain labels:

  • Recommended maximum: 14 characters each. The actual underlying requirement is a total of 28 characters across both domain labels (excluding the period between the labels). For example, both of these are acceptable: subnetad1.verylongvcnphx or verylongsubnetad1.vcnphx. For simplicity, the recommendation is 14 characters each.
  • No hyphens or underscores.
  • Recommended: include the region name in the VCN's domain label, and include the availability domain name in the subnet's domain label.

  • In general, the FQDN has a maximum total limit of 63 characters. Here is a safe general rule:

    <12_chars_max>-######.<14_chars_max>.<14_chars_max>.oraclevcn.com

The preceding maximums are not enforced when you create the VCN and subnets. However, if the labels exceed the maximum, the Exadata deployment fails.

DNS: Between On-Premises Network and VCN

Oracle recommends using a private DNS resolver to enable the use of hostnames when on-premises hosts and VCN resources communicate with each other. See Private DNS resolvers for information on creating and using private resolvers. For a reference architecture see Use private DNS in your VCN in the Oracle Architecture Center.

Node Access to Object Storage: Static Route

To be able to back up databases, and patch and update cloud tools on an Exadata Cloud Infrastructure instance, you must configure access to Oracle Cloud Infrastructure Object Storage. Regardless of how you configure the VCN with that access (for example, with a service gateway), you may also need to configure a static route to Object Storage on each of the compute nodes in the cluster. This is only required if you are not using automatic backups. If you are using customized backups using the backup APIs, then you must route traffic destined for Object Storage through the backup interface (BONDETH1). This is not necessary if you are using the automatic backups created with the Console, APIs, or CLIs.

Caution:

You must configure a static route for Object Storage access on each compute node in an Exadata Cloud Infrastructure instance if you are not creating automatic backups with the Console, APIs, or CLIs. Otherwise, attempts to back up databases, and patch or update tools on the system, can fail.
Note

When you enable the first automatic backup for a database the static route configuration will be automatically done on the service.

If you want to patch the service before creating a database, the manual static route is required to be able to patch the GI or DB Home.

The static route may also be required to access other services (IAM, KMS) if these are not reachable via client subnet and only the backup subnet uses the setting to access all servcies within a region.

Object Storage IP allocations

To configure a static route for Object Storage access

Service Gateway for the VCN

Your VCN needs access to both Object Storage for backups and Oracle YUM repos for OS updates.

Depending on whether you use Option1: Public Client Subnet with Internet Gateway or Option 2: Private Subnets described previously, you use the service gateway in different ways. See the next two sections.

Option 1: Service Gateway Access to OCI Services

Option 2: Service Gateway Access to Both Object Storage and YUM Repos

Security Rules for the Oracle Exadata Database Service on Dedicated Infrastructure

This section lists the security rules to use with your Exadata Cloud Infrastructure. Security rules control the types of traffic allowed for the client network and backup network of the Exadata's compute nodes. The rules are divided into three sections.

There are different ways to implement these rules. For more information, see Ways to Implement the Security Rules.
Note

For X8M systems, Oracle recommends that all ports on the client subnet need to be open for ingress and egress traffic. This is a requirement for adding additional database servers to the system.

Rules Required for Both the Client Network and Backup Network

This section has several general rules that enable essential connectivity for hosts in the VCN.

If you use security lists to implement your security rules, be aware that the rules that follow are included by default in the default security list. Update or replace the list to meet your particular security needs. The two ICMP rules (general ingress rules 2 and 3) are required for proper functioning of network traffic within the Oracle Cloud Infrastructure environment. Adjust the general ingress rule 1 (the SSH rule) and the general egress rule 1 to allow traffic only to and from hosts that require communication with resources in your VCN.

Rules Required Specifically for the Client Network

The following security rules are important for the client network.

Note

  • Client ingress rules 1 and 2 only cover connections initiated from within the client subnet. If you have a client that resides outside the VCN, Oracle recommends setting up two additional similar rules that instead have the Source CIDR set to the public IP address of the client.
  • Client ingress rules 3 and 4 and client egress rules 1 and 2 allow TCP and ICMP traffic inside the client network and enable the nodes to communicate with each other. If TCP connectivity fails across the nodes, the Exadata cloud VM cluster or DB system resource fails to provision.

Rule Required Specifically for the Backup Network

The following security rule is important for the backup network because it enables the DB system to communicate with Object Storage through the service gateway (and optionally with the Oracle YUM repos if the client network doesn't have access to them). It is redundant with the general egress rule in this topic (and in the default security list). It is optional but recommended in case the general egress rule (or default security list) is inadvertently changed.

Rules Required for Both the Client Network and Backup Network

This topic has several general rules that enable essential connectivity for hosts in the VCN.

If you use security lists to implement your security rules, be aware that the rules that follow are included by default in the default security list. Update or replace the list to meet your particular security needs. The two ICMP rules (general ingress rules 2 and 3) are required for proper functioning of network traffic within the Oracle Cloud Infrastructure environment. Adjust the general ingress rule 1 (the SSH rule) and the general egress rule 1 to allow traffic only to and from hosts that require communication with resources in your VCN.

General ingress rule 1: Allows SSH traffic from anywhere
General ingress rule 2: Allows Path MTU Discovery fragmentation messages
General ingress rule 3: Allows connectivity error messages within the VCN

This rule enables the hosts in the VCN to receive connectivity error messages from each other.

  • Stateless: No (all rules must be stateful)
  • Source Type: CIDR
  • Source CIDR: Your VCN's CIDR
  • IP Protocol: ICMP
  • Type: 3
  • Code: All
General egress rule 1: Allows all egress traffic

Rules Required Specifically for the Client Network

The following security rules are important for the client network.

Note

  • For X8M systems, Oracle recommends that all ports on the client subnet need to be open for ingress and egress traffic. This is a requirement for adding additional database servers to the system.
  • Client ingress rules 1 and 2 only cover connections initiated from within the client subnet. If you have a client that resides outside the VCN, Oracle recommends setting up two additional similar rules that instead have the Source CIDR set to the public IP address of the client.
  • Client ingress rules 3 and 4 and client egress rules 1 and 2 allow TCP and ICMP traffic inside the client network and enable the nodes to communicate with each other. If TCP connectivity fails across the nodes, the Exadata cloud VM cluster or DB system resource fails to provision.
Client ingress rule 1: Allows ONS and FAN traffic from within the client subnet

The first rule is recommended and enables the Oracle Notification Services (ONS) to communicate about Fast Application Notification (FAN) events.

  • Stateless: No (all rules must be stateful)
  • Source Type: CIDR
  • Source CIDR: Client subnet's CIDR
  • IP Protocol: TCP
  • Source Port Range: All
  • Destination Port Range: 6200
  • Description: An optional description of the rule.
Client ingress rule 2: Allows SQL*NET traffic from within the client subnet

This rule is for SQL*NET traffic and is required in these cases:

  • If you need to enable client connections to the database
  • If you plan to use Oracle Data Guard
  • Stateless: No (all rules must be stateful)
  • Source Type: CIDR
  • Source CIDR: Client subnet's CIDR
  • IP Protocol: TCP
  • Source Port Range: All
  • Destination Port Range: 1521
  • Description: An optional description of the rule.
Client egress rule 1: Allows all TCP traffic inside the client subnet

  • Stateless: No (all rules must be stateful)
  • Destination Type: CIDR
  • Destination CIDR: 0.0.0.0/0
  • IP Protocol: TCP
  • Source Port Range: All
  • Destination Port Range: 22
  • Description: An optional description of the rule.
Client egress rule 2: Allows all egress traffic (allows connections to the Oracle YUM repos)

Client egress rule 3 is important because it allows connections to the Oracle YUM repos.

It is redundant with the general egress rule 1: Allow all egress traffic (and in the default security list). It is optional but recommended in case the general egress rule (or default security list) is inadvertently changed.

  • Stateless: No (all rules must be stateful)
  • Destination Type: CIDR
  • Destination CIDR: 0.0.0.0/0
  • IP Protocol: All
  • Description: An optional description of the rule.

Rule Required Specifically for the Backup Network

The following security rule is important for the backup network because it enables the DB system to communicate with Object Storage through the service gateway (and optionally with the Oracle YUM repos if the client network doesn't have access to them).

It is redundant with the general egress rule 1: Allows all egress traffic in (and in the ). It is optional but recommended in case the general egress rule (or default security list) is inadvertently changed.

Backup egress rule: Allows access to Object Storage

Rules Required for Events Service

The compute instance must have either a public IP address or a service gateway to be able to send compute instance metrics to the Events service.

The default egress rules are sufficient to to allow the compute instance to send compute instance metrics to the Events service.

If the instance does not have a public IP address, set up a service gateway on the virtual cloud network (VCN). The service gateway lets the instance send compute instance metrics to the Events service without the traffic going over the internet. Here are special notes for setting up the service gateway to access the Events service:

  • When creating the service gateway, enable the service label called All <region> Services in Oracle Services Network. It includes the Events service.
  • When setting up routing for the subnet that contains the instance, set up a route rule with Target Type set to Service Gateway, and the Destination Service set to All <region> Services in Oracle Services Network.

    For detailed instructions, see Access to Oracle Services: Service Gateway.

Rules Required for Monitoring Service

The compute instance must have either a public IP address or a service gateway to be able to send compute instance metrics to the Monitoring service.

The default egress rules are sufficient to to allow the compute instance to send compute instance metrics to the Monitoring service.

If the instance does not have a public IP address, set up a service gateway on the virtual cloud network (VCN). The service gateway lets the instance send compute instance metrics to the Monitoring service without the traffic going over the internet. Here are special notes for setting up the service gateway to access the Monitoring service:

  • When creating the service gateway, enable the service label called All <region> Services in Oracle Services Network. It includes the Monitoring service.
  • When setting up routing for the subnet that contains the instance, set up a route rule with Target Type set to Service Gateway, and the Destination Service set to All <region> Services in Oracle Services Network.

    For detailed instructions, see Access to Oracle Services: Service Gateway.

Ways to Implement the Security Rules

The Networking service offers two ways to implement security rules within your VCN:

For a comparison of the two methods, see Comaprison of Security Lists and Network Security Groups.

If you use network security groups

If you use security lists