Chapter 27. OpenShift SDN network plugin 27.1. About the OpenShift SDN network plugin Part of Red Hat OpenShift Networking, OpenShift SDN is a network plugin that uses a software-defined networking (SDN) approach to provide a unified cluster network that enables communication between pods across the OpenShift Container Platform cluster. This pod network is established and maintained by OpenShift SDN, which configures an overlay network using Open vSwitch (OVS). Note OpenShift SDN CNI is deprecated as of OpenShift Container Platform 4.14. As of OpenShift Container Platform 4.15, the network plugin is not an option for new installations. In a subsequent future release, the OpenShift SDN network plugin is planned to be removed and no longer supported. Red Hat will provide bug fixes and support for this feature until it is removed, but this feature will no longer receive enhancements. As an alternative to OpenShift SDN CNI, you can use OVN Kubernetes CNI instead. 27.1.1. OpenShift SDN network isolation modes OpenShift SDN provides three SDN modes for configuring the pod network: Network policy mode allows project administrators to configure their own isolation policies using NetworkPolicy objects. Network policy is the default mode in OpenShift Container Platform 4.15. Multitenant mode provides project-level isolation for pods and services. Pods from different projects cannot send packets to or receive packets from pods and services of a different project. You can disable isolation for a project, allowing it to send network traffic to all pods and services in the entire cluster and receive network traffic from those pods and services. Subnet mode provides a flat pod network where every pod can communicate with every other pod and service. The network policy mode provides the same functionality as subnet mode. 27.1.2. Supported network plugin feature matrix Red Hat OpenShift Networking offers two options for the network plugin, OpenShift SDN and OVN-Kubernetes, for the network plugin. The following table summarizes the current feature support for both network plugins: Table 27.1. Default CNI network plugin feature comparison Feature OpenShift SDN OVN-Kubernetes Egress IPs Supported Supported Egress firewall Supported Supported [1] Egress router Supported Supported [2] Hybrid networking Not supported Supported IPsec encryption for intra-cluster communication Not supported Supported IPv4 single-stack Supported Supported IPv6 single-stack Not supported Supported [3] IPv4/IPv6 dual-stack Not Supported Supported [4] IPv6/IPv4 dual-stack Not supported Supported [5] Kubernetes network policy Supported Supported Kubernetes network policy logs Not supported Supported Hardware offloading Not supported Supported Multicast Supported Supported Egress firewall is also known as egress network policy in OpenShift SDN. This is not the same as network policy egress. Egress router for OVN-Kubernetes supports only redirect mode. IPv6 single-stack networking on a bare-metal platform. IPv4/IPv6 dual-stack networking on bare-metal, VMware vSphere (installer-provisioned infrastructure installations only), IBM Power(R), IBM Z(R), and RHOSP platforms. IPv6/IPv4 dual-stack networking on bare-metal, VMware vSphere (installer-provisioned infrastructure installations only), and IBM Power(R) platforms. 27.2. Configuring egress IPs for a project As a cluster administrator, you can configure the OpenShift SDN Container Network Interface (CNI) network plugin to assign one or more egress IP addresses to a project. Note OpenShift SDN CNI is deprecated as of OpenShift Container Platform 4.14. As of OpenShift Container Platform 4.15, the network plugin is not an option for new installations. In a subsequent future release, the OpenShift SDN network plugin is planned to be removed and no longer supported. Red Hat will provide bug fixes and support for this feature until it is removed, but this feature will no longer receive enhancements. As an alternative to OpenShift SDN CNI, you can use OVN Kubernetes CNI instead. 27.2.1. Egress IP address architectural design and implementation The OpenShift Container Platform egress IP address functionality allows you to ensure that the traffic from one or more pods in one or more namespaces has a consistent source IP address for services outside the cluster network. For example, you might have a pod that periodically queries a database that is hosted on a server outside of your cluster. To enforce access requirements for the server, a packet filtering device is configured to allow traffic only from specific IP addresses. To ensure that you can reliably allow access to the server from only that specific pod, you can configure a specific egress IP address for the pod that makes the requests to the server. An egress IP address assigned to a namespace is different from an egress router, which is used to send traffic to specific destinations. In some cluster configurations, application pods and ingress router pods run on the same node. If you configure an egress IP address for an application project in this scenario, the IP address is not used when you send a request to a route from the application project. An egress IP address is implemented as an additional IP address on the primary network interface of a node and must be in the same subnet as the primary IP address of the node. The additional IP address must not be assigned to any other node in the cluster. Important Egress IP addresses must not be configured in any Linux network configuration files, such as ifcfg-eth0 . 27.2.1.1. Platform support Support for the egress IP address functionality on various platforms is summarized in the following table: Platform Supported Bare metal Yes VMware vSphere Yes Red Hat OpenStack Platform (RHOSP) Yes Amazon Web Services (AWS) Yes Google Cloud Platform (GCP) Yes Microsoft Azure Yes IBM Z(R) and IBM(R) LinuxONE Yes IBM Z(R) and IBM(R) LinuxONE for Red Hat Enterprise Linux (RHEL) KVM Yes IBM Power(R) Yes Nutanix Yes Important The assignment of egress IP addresses to control plane nodes with the EgressIP feature is not supported on a cluster provisioned on Amazon Web Services (AWS). ( BZ#2039656 ). 27.2.1.2. Public cloud platform considerations For clusters provisioned on public cloud infrastructure, there is a constraint on the absolute number of assignable IP addresses per node. The maximum number of assignable IP addresses per node, or the IP capacity , can be described in the following formula: IP capacity = public cloud default capacity - sum(current IP assignments) While the Egress IPs capability manages the IP address capacity per node, it is important to plan for this constraint in your deployments. For example, for a cluster installed on bare-metal infrastructure with 8 nodes you can configure 150 egress IP addresses. However, if a public cloud provider limits IP address capacity to 10 IP addresses per node, the total number of assignable IP addresses is only 80. To achieve the same IP address capacity in this example cloud provider, you would need to allocate 7 additional nodes. To confirm the IP capacity and subnets for any node in your public cloud environment, you can enter the oc get node <node_name> -o yaml command. The cloud.network.openshift.io/egress-ipconfig annotation includes capacity and subnet information for the node. The annotation value is an array with a single object with fields that provide the following information for the primary network interface: interface : Specifies the interface ID on AWS and Azure and the interface name on GCP. ifaddr : Specifies the subnet mask for one or both IP address families. capacity : Specifies the IP address capacity for the node. On AWS, the IP address capacity is provided per IP address family. On Azure and GCP, the IP address capacity includes both IPv4 and IPv6 addresses. Automatic attachment and detachment of egress IP addresses for traffic between nodes are available. This allows for traffic from many pods in namespaces to have a consistent source IP address to locations outside of the cluster. This also supports OpenShift SDN and OVN-Kubernetes, which is the default networking plugin in Red Hat OpenShift Networking in OpenShift Container Platform 4.15. Note The RHOSP egress IP address feature creates a Neutron reservation port called egressip-<IP address> . Using the same RHOSP user as the one used for the OpenShift Container Platform cluster installation, you can assign a floating IP address to this reservation port to have a predictable SNAT address for egress traffic. When an egress IP address on an RHOSP network is moved from one node to another, because of a node failover, for example, the Neutron reservation port is removed and recreated. This means that the floating IP association is lost and you need to manually reassign the floating IP address to the new reservation port. Note When an RHOSP cluster administrator assigns a floating IP to the reservation port, OpenShift Container Platform cannot delete the reservation port. The CloudPrivateIPConfig object cannot perform delete and move operations until an RHOSP cluster administrator unassigns the floating IP from the reservation port. The following examples illustrate the annotation from nodes on several public cloud providers. The annotations are indented for readability. Example cloud.network.openshift.io/egress-ipconfig annotation on AWS cloud.network.openshift.io/egress-ipconfig: [ { "interface":"eni-078d267045138e436", "ifaddr":{"ipv4":"10.0.128.0/18"}, "capacity":{"ipv4":14,"ipv6":15} } ] Example cloud.network.openshift.io/egress-ipconfig annotation on GCP cloud.network.openshift.io/egress-ipconfig: [ { "interface":"nic0", "ifaddr":{"ipv4":"10.0.128.0/18"}, "capacity":{"ip":14} } ] The following sections describe the IP address capacity for supported public cloud environments for use in your capacity calculation. 27.2.1.2.1. Amazon Web Services (AWS) IP address capacity limits On AWS, constraints on IP address assignments depend on the instance type configured. For more information, see IP addresses per network interface per instance type 27.2.1.2.2. Google Cloud Platform (GCP) IP address capacity limits On GCP, the networking model implements additional node IP addresses through IP address aliasing, rather than IP address assignments. However, IP address capacity maps directly to IP aliasing capacity. The following capacity limits exist for IP aliasing assignment: Per node, the maximum number of IP aliases, both IPv4 and IPv6, is 100. Per VPC, the maximum number of IP aliases is unspecified, but OpenShift Container Platform scalability testing reveals the maximum to be approximately 15,000. For more information, see Per instance quotas and Alias IP ranges overview . 27.2.1.2.3. Microsoft Azure IP address capacity limits On Azure, the following capacity limits exist for IP address assignment: Per NIC, the maximum number of assignable IP addresses, for both IPv4 and IPv6, is 256. Per virtual network, the maximum number of assigned IP addresses cannot exceed 65,536. For more information, see Networking limits . 27.2.1.3. Limitations The following limitations apply when using egress IP addresses with the OpenShift SDN network plugin: You cannot use manually assigned and automatically assigned egress IP addresses on the same nodes. If you manually assign egress IP addresses from an IP address range, you must not make that range available for automatic IP assignment. You cannot share egress IP addresses across multiple namespaces using the OpenShift SDN egress IP address implementation. If you need to share IP addresses across namespaces, the OVN-Kubernetes network plugin egress IP address implementation allows you to span IP addresses across multiple namespaces. Note If you use OpenShift SDN in multitenant mode, you cannot use egress IP addresses with any namespace that is joined to another namespace by the projects that are associated with them. For example, if project1 and project2 are joined by running the oc adm pod-network join-projects --to=project1 project2 command, neither project can use an egress IP address. For more information, see BZ#1645577 . 27.2.1.4. IP address assignment approaches You can assign egress IP addresses to namespaces by setting the egressIPs parameter of the NetNamespace object. After an egress IP address is associated with a project, OpenShift SDN allows you to assign egress IP addresses to hosts in two ways: In the automatically assigned approach, an egress IP address range is assigned to a node. In the manually assigned approach, a list of one or more egress IP address is assigned to a node. Namespaces that request an egress IP address are matched with nodes that can host those egress IP addresses, and then the egress IP addresses are assigned to those nodes. If the egressIPs parameter is set on a NetNamespace object, but no node hosts that egress IP address, then egress traffic from the namespace will be dropped. High availability of nodes is automatic. If a node that hosts an egress IP address is unreachable and there are nodes that are able to host that egress IP address, then the egress IP address will move to a new node. When the unreachable node comes back online, the egress IP address automatically moves to balance egress IP addresses across nodes. 27.2.1.4.1. Considerations when using automatically assigned egress IP addresses When using the automatic assignment approach for egress IP addresses the following considerations apply: You set the egressCIDRs parameter of each node's HostSubnet resource to indicate the range of egress IP addresses that can be hosted by a node. OpenShift Container Platform sets the egressIPs parameter of the HostSubnet resource based on the IP address range you specify. If the node hosting the namespace's egress IP address is unreachable, OpenShift Container Platform will reassign the egress IP address to another node with a compatible egress IP address range. The automatic assignment approach works best for clusters installed in environments with flexibility in associating additional IP addresses with nodes. 27.2.1.4.2. Considerations when using manually assigned egress IP addresses This approach allows you to control which nodes can host an egress IP address. Note If your cluster is installed on public cloud infrastructure, you must ensure that each node that you assign egress IP addresses to has sufficient spare capacity to host the IP addresses. For more information, see "Platform considerations" in a section. When using the manual assignment approach for egress IP addresses the following considerations apply: You set the egressIPs parameter of each node's HostSubnet resource to indicate the IP addresses that can be hosted by a node. Multiple egress IP addresses per namespace are supported. If a namespace has multiple egress IP addresses and those addresses are hosted on multiple nodes, the following additional considerations apply: If a pod is on a node that is hosting an egress IP address, that pod always uses the egress IP address on the node. If a pod is not on a node that is hosting an egress IP address, that pod uses an egress IP address at random. 27.2.2. Configuring automatically assigned egress IP addresses for a namespace In OpenShift Container Platform you can enable automatic assignment of an egress IP address for a specific namespace across one or more nodes. Prerequisites You have access to the cluster as a user with the cluster-admin role. You have installed the OpenShift CLI ( oc ). Procedure Update the NetNamespace object with the egress IP address using the following JSON: USD oc patch netnamespace <project_name> --type=merge -p \ '{ "egressIPs": [ "<ip_address>" ] }' where: <project_name> Specifies the name of the project. <ip_address> Specifies one or more egress IP addresses for the egressIPs array. For example, to assign project1 to an IP address of 192.168.1.100 and project2 to an IP address of 192.168.1.101: USD oc patch netnamespace project1 --type=merge -p \ '{"egressIPs": ["192.168.1.100"]}' USD oc patch netnamespace project2 --type=merge -p \ '{"egressIPs": ["192.168.1.101"]}' Note Because OpenShift SDN manages the NetNamespace object, you can make changes only by modifying the existing NetNamespace object. Do not create a new NetNamespace object. Indicate which nodes can host egress IP addresses by setting the egressCIDRs parameter for each host using the following JSON: USD oc patch hostsubnet <node_name> --type=merge -p \ '{ "egressCIDRs": [ "<ip_address_range>", "<ip_address_range>" ] }' where: <node_name> Specifies a node name. <ip_address_range> Specifies an IP address range in CIDR format. You can specify more than one address range for the egressCIDRs array. For example, to set node1 and node2 to host egress IP addresses in the range 192.168.1.0 to 192.168.1.255: USD oc patch hostsubnet node1 --type=merge -p \ '{"egressCIDRs": ["192.168.1.0/24"]}' USD oc patch hostsubnet node2 --type=merge -p \ '{"egressCIDRs": ["192.168.1.0/24"]}' OpenShift Container Platform automatically assigns specific egress IP addresses to available nodes in a balanced way. In this case, it assigns the egress IP address 192.168.1.100 to node1 and the egress IP address 192.168.1.101 to node2 or vice versa. 27.2.3. Configuring manually assigned egress IP addresses for a namespace In OpenShift Container Platform you can associate one or more egress IP addresses with a namespace. Prerequisites You have access to the cluster as a user with the cluster-admin role. You have installed the OpenShift CLI ( oc ). Procedure Update the NetNamespace object by specifying the following JSON object with the desired IP addresses: USD oc patch netnamespace <project_name> --type=merge -p \ '{ "egressIPs": [ "<ip_address>" ] }' where: <project_name> Specifies the name of the project. <ip_address> Specifies one or more egress IP addresses for the egressIPs array. For example, to assign the project1 project to the IP addresses 192.168.1.100 and 192.168.1.101 : USD oc patch netnamespace project1 --type=merge \ -p '{"egressIPs": ["192.168.1.100","192.168.1.101"]}' To provide high availability, set the egressIPs value to two or more IP addresses on different nodes. If multiple egress IP addresses are set, then pods use all egress IP addresses roughly equally. Note Because OpenShift SDN manages the NetNamespace object, you can make changes only by modifying the existing NetNamespace object. Do not create a new NetNamespace object. Manually assign the egress IP address to the node hosts. If your cluster is installed on public cloud infrastructure, you must confirm that the node has available IP address capacity. Set the egressIPs parameter on the HostSubnet object on the node host. Using the following JSON, include as many IP addresses as you want to assign to that node host: USD oc patch hostsubnet <node_name> --type=merge -p \ '{ "egressIPs": [ "<ip_address>", "<ip_address>" ] }' where: <node_name> Specifies a node name. <ip_address> Specifies an IP address. You can specify more than one IP address for the egressIPs array. For example, to specify that node1 should have the egress IPs 192.168.1.100 , 192.168.1.101 , and 192.168.1.102 : USD oc patch hostsubnet node1 --type=merge -p \ '{"egressIPs": ["192.168.1.100", "192.168.1.101", "192.168.1.102"]}' In the example, all egress traffic for project1 will be routed to the node hosting the specified egress IP, and then connected through Network Address Translation (NAT) to that IP address. 27.2.4. Additional resources If you are configuring manual egress IP address assignment, see Platform considerations for information about IP capacity planning. 27.3. Configuring an egress firewall for a project As a cluster administrator, you can create an egress firewall for a project that restricts egress traffic leaving your OpenShift Container Platform cluster. Note OpenShift SDN CNI is deprecated as of OpenShift Container Platform 4.14. As of OpenShift Container Platform 4.15, the network plugin is not an option for new installations. In a subsequent future release, the OpenShift SDN network plugin is planned to be removed and no longer supported. Red Hat will provide bug fixes and support for this feature until it is removed, but this feature will no longer receive enhancements. As an alternative to OpenShift SDN CNI, you can use OVN Kubernetes CNI instead. 27.3.1. How an egress firewall works in a project As a cluster administrator, you can use an egress firewall to limit the external hosts that some or all pods can access from within the cluster. An egress firewall supports the following scenarios: A pod can only connect to internal hosts and cannot initiate connections to the public internet. A pod can only connect to the public internet and cannot initiate connections to internal hosts that are outside the OpenShift Container Platform cluster. A pod cannot reach specified internal subnets or hosts outside the OpenShift Container Platform cluster. A pod can connect to only specific external hosts. For example, you can allow one project access to a specified IP range but deny the same access to a different project. Or you can restrict application developers from updating from Python pip mirrors, and force updates to come only from approved sources. Note Egress firewall does not apply to the host network namespace. Pods with host networking enabled are unaffected by egress firewall rules. You configure an egress firewall policy by creating an EgressNetworkPolicy custom resource (CR) object. The egress firewall matches network traffic that meets any of the following criteria: An IP address range in CIDR format A DNS name that resolves to an IP address Important If your egress firewall includes a deny rule for 0.0.0.0/0 , access to your OpenShift Container Platform API servers is blocked. You must either add allow rules for each IP address or use the nodeSelector type allow rule in your egress policy rules to connect to API servers. The following example illustrates the order of the egress firewall rules necessary to ensure API server access: apiVersion: network.openshift.io/v1 kind: EgressNetworkPolicy metadata: name: default namespace: <namespace> 1 spec: egress: - to: cidrSelector: <api_server_address_range> 2 type: Allow # ... - to: cidrSelector: 0.0.0.0/0 3 type: Deny 1 The namespace for the egress firewall. 2 The IP address range that includes your OpenShift Container Platform API servers. 3 A global deny rule prevents access to the OpenShift Container Platform API servers. To find the IP address for your API servers, run oc get ep kubernetes -n default . For more information, see BZ#1988324 . Important You must have OpenShift SDN configured to use either the network policy or multitenant mode to configure an egress firewall. If you use network policy mode, an egress firewall is compatible with only one policy per namespace and will not work with projects that share a network, such as global projects. Warning Egress firewall rules do not apply to traffic that goes through routers. Any user with permission to create a Route CR object can bypass egress firewall policy rules by creating a route that points to a forbidden destination. 27.3.1.1. Limitations of an egress firewall An egress firewall has the following limitations: No project can have more than one EgressNetworkPolicy object. Important The creation of more than one EgressNetworkPolicy object is allowed, however it should not be done. When you create more than one EgressNetworkPolicy object, the following message is returned: dropping all rules . In actuality, all external traffic is dropped, which can cause security risks for your organization. A maximum of one EgressNetworkPolicy object with a maximum of 1,000 rules can be defined per project. The default project cannot use an egress firewall. When using the OpenShift SDN network plugin in multitenant mode, the following limitations apply: Global projects cannot use an egress firewall. You can make a project global by using the oc adm pod-network make-projects-global command. Projects merged by using the oc adm pod-network join-projects command cannot use an egress firewall in any of the joined projects. If you create a selectorless service and manually define endpoints or EndpointSlices that point to external IPs, traffic to the service IP might still be allowed, even if your EgressNetworkPolicy is configured to deny all egress traffic. This occurs because OpenShift SDN does not fully enforce egress network policies for these external endpoints. Consequently, this might result in unexpected access to external services. Violating any of these restrictions results in a broken egress firewall for the project. Consequently, all external network traffic is dropped, which can cause security risks for your organization. An Egress Firewall resource can be created in the kube-node-lease , kube-public , kube-system , openshift and openshift- projects. 27.3.1.2. Matching order for egress firewall policy rules The egress firewall policy rules are evaluated in the order that they are defined, from first to last. The first rule that matches an egress connection from a pod applies. Any subsequent rules are ignored for that connection. 27.3.1.3. How Domain Name Server (DNS) resolution works If you use DNS names in any of your egress firewall policy rules, proper resolution of the domain names is subject to the following restrictions: Domain name updates are polled based on a time-to-live (TTL) duration. By default, the duration is 30 seconds. When the egress firewall controller queries the local name servers for a domain name, if the response includes a TTL that is less than 30 seconds, the controller sets the duration to the returned value. If the TTL in the response is greater than 30 minutes, the controller sets the duration to 30 minutes. If the TTL is between 30 seconds and 30 minutes, the controller ignores the value and sets the duration to 30 seconds. The pod must resolve the domain from the same local name servers when necessary. Otherwise the IP addresses for the domain known by the egress firewall controller and the pod can be different. If the IP addresses for a hostname differ, the egress firewall might not be enforced consistently. Because the egress firewall controller and pods asynchronously poll the same local name server, the pod might obtain the updated IP address before the egress controller does, which causes a race condition. Due to this current limitation, domain name usage in EgressNetworkPolicy objects is only recommended for domains with infrequent IP address changes. Note Using DNS names in your egress firewall policy does not affect local DNS resolution through CoreDNS. However, if your egress firewall policy uses domain names, and an external DNS server handles DNS resolution for an affected pod, you must include egress firewall rules that permit access to the IP addresses of your DNS server. 27.3.2. EgressNetworkPolicy custom resource (CR) object You can define one or more rules for an egress firewall. A rule is either an Allow rule or a Deny rule, with a specification for the traffic that the rule applies to. The following YAML describes an EgressNetworkPolicy CR object: EgressNetworkPolicy object apiVersion: network.openshift.io/v1 kind: EgressNetworkPolicy metadata: name: <name> 1 spec: egress: 2 ... 1 A name for your egress firewall policy. 2 A collection of one or more egress network policy rules as described in the following section. 27.3.2.1. EgressNetworkPolicy rules The following YAML describes an egress firewall rule object. The user can select either an IP address range in CIDR format, a domain name, or use the nodeSelector to allow or deny egress traffic. The egress stanza expects an array of one or more objects. Egress policy rule stanza egress: - type: <type> 1 to: 2 cidrSelector: <cidr> 3 dnsName: <dns_name> 4 1 The type of rule. The value must be either Allow or Deny . 2 A stanza describing an egress traffic match rule. A value for either the cidrSelector field or the dnsName field for the rule. You cannot use both fields in the same rule. 3 An IP address range in CIDR format. 4 A domain name. 27.3.2.2. Example EgressNetworkPolicy CR objects The following example defines several egress firewall policy rules: apiVersion: network.openshift.io/v1 kind: EgressNetworkPolicy metadata: name: default spec: egress: 1 - type: Allow to: cidrSelector: 1.2.3.0/24 - type: Allow to: dnsName: www.example.com - type: Deny to: cidrSelector: 0.0.0.0/0 1 A collection of egress firewall policy rule objects. 27.3.3. Creating an egress firewall policy object As a cluster administrator, you can create an egress firewall policy object for a project. Important If the project already has an EgressNetworkPolicy object defined, you must edit the existing policy to make changes to the egress firewall rules. Prerequisites A cluster that uses the OpenShift SDN network plugin. Install the OpenShift CLI ( oc ). You must log in to the cluster as a cluster administrator. Procedure Create a policy rule: Create a <policy_name>.yaml file where <policy_name> describes the egress policy rules. In the file you created, define an egress policy object. Enter the following command to create the policy object. Replace <policy_name> with the name of the policy and <project> with the project that the rule applies to. USD oc create -f <policy_name>.yaml -n <project> In the following example, a new EgressNetworkPolicy object is created in a project named project1 : USD oc create -f default.yaml -n project1 Example output egressnetworkpolicy.network.openshift.io/v1 created Optional: Save the <policy_name>.yaml file so that you can make changes later. 27.4. Editing an egress firewall for a project As a cluster administrator, you can modify network traffic rules for an existing egress firewall. 27.4.1. Viewing an EgressNetworkPolicy object You can view an EgressNetworkPolicy object in your cluster. Prerequisites A cluster using the OpenShift SDN network plugin. Install the OpenShift Command-line Interface (CLI), commonly known as oc . You must log in to the cluster. Procedure Optional: To view the names of the EgressNetworkPolicy objects defined in your cluster, enter the following command: USD oc get egressnetworkpolicy --all-namespaces To inspect a policy, enter the following command. Replace <policy_name> with the name of the policy to inspect. USD oc describe egressnetworkpolicy <policy_name> Example output Name: default Namespace: project1 Created: 20 minutes ago Labels: <none> Annotations: <none> Rule: Allow to 1.2.3.0/24 Rule: Allow to www.example.com Rule: Deny to 0.0.0.0/0 27.5. Editing an egress firewall for a project As a cluster administrator, you can modify network traffic rules for an existing egress firewall. Note OpenShift SDN CNI is deprecated as of OpenShift Container Platform 4.14. As of OpenShift Container Platform 4.15, the network plugin is not an option for new installations. In a subsequent future release, the OpenShift SDN network plugin is planned to be removed and no longer supported. Red Hat will provide bug fixes and support for this feature until it is removed, but this feature will no longer receive enhancements. As an alternative to OpenShift SDN CNI, you can use OVN Kubernetes CNI instead. 27.5.1. Editing an EgressNetworkPolicy object As a cluster administrator, you can update the egress firewall for a project. Prerequisites A cluster using the OpenShift SDN network plugin. Install the OpenShift CLI ( oc ). You must log in to the cluster as a cluster administrator. Procedure Find the name of the EgressNetworkPolicy object for the project. Replace <project> with the name of the project. USD oc get -n <project> egressnetworkpolicy Optional: If you did not save a copy of the EgressNetworkPolicy object when you created the egress network firewall, enter the following command to create a copy. USD oc get -n <project> egressnetworkpolicy <name> -o yaml > <filename>.yaml Replace <project> with the name of the project. Replace <name> with the name of the object. Replace <filename> with the name of the file to save the YAML to. After making changes to the policy rules, enter the following command to replace the EgressNetworkPolicy object. Replace <filename> with the name of the file containing the updated EgressNetworkPolicy object. USD oc replace -f <filename>.yaml 27.6. Removing an egress firewall from a project As a cluster administrator, you can remove an egress firewall from a project to remove all restrictions on network traffic from the project that leaves the OpenShift Container Platform cluster. Note OpenShift SDN CNI is deprecated as of OpenShift Container Platform 4.14. As of OpenShift Container Platform 4.15, the network plugin is not an option for new installations. In a subsequent future release, the OpenShift SDN network plugin is planned to be removed and no longer supported. Red Hat will provide bug fixes and support for this feature until it is removed, but this feature will no longer receive enhancements. As an alternative to OpenShift SDN CNI, you can use OVN Kubernetes CNI instead. 27.6.1. Removing an EgressNetworkPolicy object As a cluster administrator, you can remove an egress firewall from a project. Prerequisites A cluster using the OpenShift SDN network plugin. Install the OpenShift CLI ( oc ). You must log in to the cluster as a cluster administrator. Procedure Find the name of the EgressNetworkPolicy object for the project. Replace <project> with the name of the project. USD oc get -n <project> egressnetworkpolicy Enter the following command to delete the EgressNetworkPolicy object. Replace <project> with the name of the project and <name> with the name of the object. USD oc delete -n <project> egressnetworkpolicy <name> 27.7. Considerations for the use of an egress router pod 27.7.1. About an egress router pod The OpenShift Container Platform egress router pod redirects traffic to a specified remote server from a private source IP address that is not used for any other purpose. An egress router pod can send network traffic to servers that are set up to allow access only from specific IP addresses. Note The egress router pod is not intended for every outgoing connection. Creating large numbers of egress router pods can exceed the limits of your network hardware. For example, creating an egress router pod for every project or application could exceed the number of local MAC addresses that the network interface can handle before reverting to filtering MAC addresses in software. Important The egress router image is not compatible with Amazon AWS, Azure Cloud, or any other cloud platform that does not support layer 2 manipulations due to their incompatibility with macvlan traffic. 27.7.1.1. Egress router modes In redirect mode , an egress router pod configures iptables rules to redirect traffic from its own IP address to one or more destination IP addresses. Client pods that need to use the reserved source IP address must be configured to access the service for the egress router rather than connecting directly to the destination IP. You can access the destination service and port from the application pod by using the curl command. For example: USD curl <router_service_IP> <port> In HTTP proxy mode , an egress router pod runs as an HTTP proxy on port 8080 . This mode only works for clients that are connecting to HTTP-based or HTTPS-based services, but usually requires fewer changes to the client pods to get them to work. Many programs can be told to use an HTTP proxy by setting an environment variable. In DNS proxy mode , an egress router pod runs as a DNS proxy for TCP-based services from its own IP address to one or more destination IP addresses. To make use of the reserved, source IP address, client pods must be modified to connect to the egress router pod rather than connecting directly to the destination IP address. This modification ensures that external destinations treat traffic as though it were coming from a known source. Redirect mode works for all services except for HTTP and HTTPS. For HTTP and HTTPS services, use HTTP proxy mode. For TCP-based services with IP addresses or domain names, use DNS proxy mode. 27.7.1.2. Egress router pod implementation The egress router pod setup is performed by an initialization container. That container runs in a privileged context so that it can configure the macvlan interface and set up iptables rules. After the initialization container finishes setting up the iptables rules, it exits. the egress router pod executes the container to handle the egress router traffic. The image used varies depending on the egress router mode. The environment variables determine which addresses the egress-router image uses. The image configures the macvlan interface to use EGRESS_SOURCE as its IP address, with EGRESS_GATEWAY as the IP address for the gateway. Network Address Translation (NAT) rules are set up so that connections to the cluster IP address of the pod on any TCP or UDP port are redirected to the same port on IP address specified by the EGRESS_DESTINATION variable. If only some of the nodes in your cluster are capable of claiming the specified source IP address and using the specified gateway, you can specify a nodeName or nodeSelector to identify which nodes are acceptable. 27.7.1.3. Deployment considerations An egress router pod adds an additional IP address and MAC address to the primary network interface of the node. As a result, you might need to configure your hypervisor or cloud provider to allow the additional address. Red Hat OpenStack Platform (RHOSP) If you deploy OpenShift Container Platform on RHOSP, you must allow traffic from the IP and MAC addresses of the egress router pod on your OpenStack environment. If you do not allow the traffic, then communication will fail : USD openstack port set --allowed-address \ ip_address=<ip_address>,mac_address=<mac_address> <neutron_port_uuid> VMware vSphere If you are using VMware vSphere, see the VMware documentation for securing vSphere standard switches . View and change VMware vSphere default settings by selecting the host virtual switch from the vSphere Web Client. Specifically, ensure that the following are enabled: MAC Address Changes Forged Transits Promiscuous Mode Operation 27.7.1.4. Failover configuration To avoid downtime, you can deploy an egress router pod with a Deployment resource, as in the following example. To create a new Service object for the example deployment, use the oc expose deployment/egress-demo-controller command. apiVersion: apps/v1 kind: Deployment metadata: name: egress-demo-controller spec: replicas: 1 1 selector: matchLabels: name: egress-router template: metadata: name: egress-router labels: name: egress-router annotations: pod.network.openshift.io/assign-macvlan: "true" spec: 2 initContainers: ... containers: ... 1 Ensure that replicas is set to 1 , because only one pod can use a given egress source IP address at any time. This means that only a single copy of the router runs on a node. 2 Specify the Pod object template for the egress router pod. 27.7.2. Additional resources Deploying an egress router in redirection mode Deploying an egress router in HTTP proxy mode Deploying an egress router in DNS proxy mode 27.8. Deploying an egress router pod in redirect mode As a cluster administrator, you can deploy an egress router pod that is configured to redirect traffic to specified destination IP addresses. 27.8.1. Egress router pod specification for redirect mode Define the configuration for an egress router pod in the Pod object. The following YAML describes the fields for the configuration of an egress router pod in redirect mode: apiVersion: v1 kind: Pod metadata: name: egress-1 labels: name: egress-1 annotations: pod.network.openshift.io/assign-macvlan: "true" 1 spec: initContainers: - name: egress-router image: registry.redhat.io/openshift4/ose-egress-router securityContext: privileged: true env: - name: EGRESS_SOURCE 2 value: <egress_router> - name: EGRESS_GATEWAY 3 value: <egress_gateway> - name: EGRESS_DESTINATION 4 value: <egress_destination> - name: EGRESS_ROUTER_MODE value: init containers: - name: egress-router-wait image: registry.redhat.io/openshift4/ose-pod 1 The annotation tells OpenShift Container Platform to create a macvlan network interface on the primary network interface controller (NIC) and move that macvlan interface into the pod's network namespace. You must include the quotation marks around the "true" value. To have OpenShift Container Platform create the macvlan interface on a different NIC interface, set the annotation value to the name of that interface. For example, eth1 . 2 IP address from the physical network that the node is on that is reserved for use by the egress router pod. Optional: You can include the subnet length, the /24 suffix, so that a proper route to the local subnet is set. If you do not specify a subnet length, then the egress router can access only the host specified with the EGRESS_GATEWAY variable and no other hosts on the subnet. 3 Same value as the default gateway used by the node. 4 External server to direct traffic to. Using this example, connections to the pod are redirected to 203.0.113.25 , with a source IP address of 192.168.12.99 . Example egress router pod specification apiVersion: v1 kind: Pod metadata: name: egress-multi labels: name: egress-multi annotations: pod.network.openshift.io/assign-macvlan: "true" spec: initContainers: - name: egress-router image: registry.redhat.io/openshift4/ose-egress-router securityContext: privileged: true env: - name: EGRESS_SOURCE value: 192.168.12.99/24 - name: EGRESS_GATEWAY value: 192.168.12.1 - name: EGRESS_DESTINATION value: | 80 tcp 203.0.113.25 8080 tcp 203.0.113.26 80 8443 tcp 203.0.113.26 443 203.0.113.27 - name: EGRESS_ROUTER_MODE value: init containers: - name: egress-router-wait image: registry.redhat.io/openshift4/ose-pod 27.8.2. Egress destination configuration format When an egress router pod is deployed in redirect mode, you can specify redirection rules by using one or more of the following formats: <port> <protocol> <ip_address> - Incoming connections to the given <port> should be redirected to the same port on the given <ip_address> . <protocol> is either tcp or udp . <port> <protocol> <ip_address> <remote_port> - As above, except that the connection is redirected to a different <remote_port> on <ip_address> . <ip_address> - If the last line is a single IP address, then any connections on any other port will be redirected to the corresponding port on that IP address. If there is no fallback IP address then connections on other ports are rejected. In the example that follows several rules are defined: The first line redirects traffic from local port 80 to port 80 on 203.0.113.25 . The second and third lines redirect local ports 8080 and 8443 to remote ports 80 and 443 on 203.0.113.26 . The last line matches traffic for any ports not specified in the rules. Example configuration 80 tcp 203.0.113.25 8080 tcp 203.0.113.26 80 8443 tcp 203.0.113.26 443 203.0.113.27 27.8.3. Deploying an egress router pod in redirect mode In redirect mode , an egress router pod sets up iptables rules to redirect traffic from its own IP address to one or more destination IP addresses. Client pods that need to use the reserved source IP address must be configured to access the service for the egress router rather than connecting directly to the destination IP. You can access the destination service and port from the application pod by using the curl command. For example: USD curl <router_service_IP> <port> Prerequisites Install the OpenShift CLI ( oc ). Log in as a user with cluster-admin privileges. Procedure Create an egress router pod. To ensure that other pods can find the IP address of the egress router pod, create a service to point to the egress router pod, as in the following example: apiVersion: v1 kind: Service metadata: name: egress-1 spec: ports: - name: http port: 80 - name: https port: 443 type: ClusterIP selector: name: egress-1 Your pods can now connect to this service. Their connections are redirected to the corresponding ports on the external server, using the reserved egress IP address. 27.8.4. Additional resources Configuring an egress router destination mappings with a ConfigMap 27.9. Deploying an egress router pod in HTTP proxy mode As a cluster administrator, you can deploy an egress router pod configured to proxy traffic to specified HTTP and HTTPS-based services. 27.9.1. Egress router pod specification for HTTP mode Define the configuration for an egress router pod in the Pod object. The following YAML describes the fields for the configuration of an egress router pod in HTTP mode: apiVersion: v1 kind: Pod metadata: name: egress-1 labels: name: egress-1 annotations: pod.network.openshift.io/assign-macvlan: "true" 1 spec: initContainers: - name: egress-router image: registry.redhat.io/openshift4/ose-egress-router securityContext: privileged: true env: - name: EGRESS_SOURCE 2 value: <egress-router> - name: EGRESS_GATEWAY 3 value: <egress-gateway> - name: EGRESS_ROUTER_MODE value: http-proxy containers: - name: egress-router-pod image: registry.redhat.io/openshift4/ose-egress-http-proxy env: - name: EGRESS_HTTP_PROXY_DESTINATION 4 value: |- ... ... 1 The annotation tells OpenShift Container Platform to create a macvlan network interface on the primary network interface controller (NIC) and move that macvlan interface into the pod's network namespace. You must include the quotation marks around the "true" value. To have OpenShift Container Platform create the macvlan interface on a different NIC interface, set the annotation value to the name of that interface. For example, eth1 . 2 IP address from the physical network that the node is on that is reserved for use by the egress router pod. Optional: You can include the subnet length, the /24 suffix, so that a proper route to the local subnet is set. If you do not specify a subnet length, then the egress router can access only the host specified with the EGRESS_GATEWAY variable and no other hosts on the subnet. 3 Same value as the default gateway used by the node. 4 A string or YAML multi-line string specifying how to configure the proxy. Note that this is specified as an environment variable in the HTTP proxy container, not with the other environment variables in the init container. 27.9.2. Egress destination configuration format When an egress router pod is deployed in HTTP proxy mode, you can specify redirection rules by using one or more of the following formats. Each line in the configuration specifies one group of connections to allow or deny: An IP address allows connections to that IP address, such as 192.168.1.1 . A CIDR range allows connections to that CIDR range, such as 192.168.1.0/24 . A hostname allows proxying to that host, such as www.example.com . A domain name preceded by *. allows proxying to that domain and all of its subdomains, such as *.example.com . A ! followed by any of the match expressions denies the connection instead. If the last line is * , then anything that is not explicitly denied is allowed. Otherwise, anything that is not allowed is denied. You can also use * to allow connections to all remote destinations. Example configuration !*.example.com !192.168.1.0/24 192.168.2.1 * 27.9.3. Deploying an egress router pod in HTTP proxy mode In HTTP proxy mode , an egress router pod runs as an HTTP proxy on port 8080 . This mode only works for clients that are connecting to HTTP-based or HTTPS-based services, but usually requires fewer changes to the client pods to get them to work. Many programs can be told to use an HTTP proxy by setting an environment variable. Prerequisites Install the OpenShift CLI ( oc ). Log in as a user with cluster-admin privileges. Procedure Create an egress router pod. To ensure that other pods can find the IP address of the egress router pod, create a service to point to the egress router pod, as in the following example: apiVersion: v1 kind: Service metadata: name: egress-1 spec: ports: - name: http-proxy port: 8080 1 type: ClusterIP selector: name: egress-1 1 Ensure the http port is set to 8080 . To configure the client pod (not the egress proxy pod) to use the HTTP proxy, set the http_proxy or https_proxy variables: apiVersion: v1 kind: Pod metadata: name: app-1 labels: name: app-1 spec: containers: env: - name: http_proxy value: http://egress-1:8080/ 1 - name: https_proxy value: http://egress-1:8080/ ... 1 The service created in the step. Note Using the http_proxy and https_proxy environment variables is not necessary for all setups. If the above does not create a working setup, then consult the documentation for the tool or software you are running in the pod. 27.9.4. Additional resources Configuring an egress router destination mappings with a ConfigMap 27.10. Deploying an egress router pod in DNS proxy mode As a cluster administrator, you can deploy an egress router pod configured to proxy traffic to specified DNS names and IP addresses. 27.10.1. Egress router pod specification for DNS mode Define the configuration for an egress router pod in the Pod object. The following YAML describes the fields for the configuration of an egress router pod in DNS mode: apiVersion: v1 kind: Pod metadata: name: egress-1 labels: name: egress-1 annotations: pod.network.openshift.io/assign-macvlan: "true" 1 spec: initContainers: - name: egress-router image: registry.redhat.io/openshift4/ose-egress-router securityContext: privileged: true env: - name: EGRESS_SOURCE 2 value: <egress-router> - name: EGRESS_GATEWAY 3 value: <egress-gateway> - name: EGRESS_ROUTER_MODE value: dns-proxy containers: - name: egress-router-pod image: registry.redhat.io/openshift4/ose-egress-dns-proxy securityContext: privileged: true env: - name: EGRESS_DNS_PROXY_DESTINATION 4 value: |- ... - name: EGRESS_DNS_PROXY_DEBUG 5 value: "1" ... 1 The annotation tells OpenShift Container Platform to create a macvlan network interface on the primary network interface controller (NIC) and move that macvlan interface into the pod's network namespace. You must include the quotation marks around the "true" value. To have OpenShift Container Platform create the macvlan interface on a different NIC interface, set the annotation value to the name of that interface. For example, eth1 . 2 IP address from the physical network that the node is on that is reserved for use by the egress router pod. Optional: You can include the subnet length, the /24 suffix, so that a proper route to the local subnet is set. If you do not specify a subnet length, then the egress router can access only the host specified with the EGRESS_GATEWAY variable and no other hosts on the subnet. 3 Same value as the default gateway used by the node. 4 Specify a list of one or more proxy destinations. 5 Optional: Specify to output the DNS proxy log output to stdout . 27.10.2. Egress destination configuration format When the router is deployed in DNS proxy mode, you specify a list of port and destination mappings. A destination may be either an IP address or a DNS name. An egress router pod supports the following formats for specifying port and destination mappings: Port and remote address You can specify a source port and a destination host by using the two field format: <port> <remote_address> . The host can be an IP address or a DNS name. If a DNS name is provided, DNS resolution occurs at runtime. For a given host, the proxy connects to the specified source port on the destination host when connecting to the destination host IP address. Port and remote address pair example 80 172.16.12.11 100 example.com Port, remote address, and remote port You can specify a source port, a destination host, and a destination port by using the three field format: <port> <remote_address> <remote_port> . The three field format behaves identically to the two field version, with the exception that the destination port can be different than the source port. Port, remote address, and remote port example 8080 192.168.60.252 80 8443 web.example.com 443 27.10.3. Deploying an egress router pod in DNS proxy mode In DNS proxy mode , an egress router pod acts as a DNS proxy for TCP-based services from its own IP address to one or more destination IP addresses. Prerequisites Install the OpenShift CLI ( oc ). Log in as a user with cluster-admin privileges. Procedure Create an egress router pod. Create a service for the egress router pod: Create a file named egress-router-service.yaml that contains the following YAML. Set spec.ports to the list of ports that you defined previously for the EGRESS_DNS_PROXY_DESTINATION environment variable. apiVersion: v1 kind: Service metadata: name: egress-dns-svc spec: ports: ... type: ClusterIP selector: name: egress-dns-proxy For example: apiVersion: v1 kind: Service metadata: name: egress-dns-svc spec: ports: - name: con1 protocol: TCP port: 80 targetPort: 80 - name: con2 protocol: TCP port: 100 targetPort: 100 type: ClusterIP selector: name: egress-dns-proxy To create the service, enter the following command: USD oc create -f egress-router-service.yaml Pods can now connect to this service. The connections are proxied to the corresponding ports on the external server, using the reserved egress IP address. 27.10.4. Additional resources Configuring an egress router destination mappings with a ConfigMap 27.11. Configuring an egress router pod destination list from a config map As a cluster administrator, you can define a ConfigMap object that specifies destination mappings for an egress router pod. The specific format of the configuration depends on the type of egress router pod. For details on the format, refer to the documentation for the specific egress router pod. 27.11.1. Configuring an egress router destination mappings with a config map For a large or frequently-changing set of destination mappings, you can use a config map to externally maintain the list. An advantage of this approach is that permission to edit the config map can be delegated to users without cluster-admin privileges. Because the egress router pod requires a privileged container, it is not possible for users without cluster-admin privileges to edit the pod definition directly. Note The egress router pod does not automatically update when the config map changes. You must restart the egress router pod to get updates. Prerequisites Install the OpenShift CLI ( oc ). Log in as a user with cluster-admin privileges. Procedure Create a file containing the mapping data for the egress router pod, as in the following example: You can put blank lines and comments into this file. Create a ConfigMap object from the file: USD oc delete configmap egress-routes --ignore-not-found USD oc create configmap egress-routes \ --from-file=destination=my-egress-destination.txt In the command, the egress-routes value is the name of the ConfigMap object to create and my-egress-destination.txt is the name of the file that the data is read from. Tip You can alternatively apply the following YAML to create the config map: apiVersion: v1 kind: ConfigMap metadata: name: egress-routes data: destination: | # Egress routes for Project "Test", version 3 80 tcp 203.0.113.25 8080 tcp 203.0.113.26 80 8443 tcp 203.0.113.26 443 # Fallback 203.0.113.27 Create an egress router pod definition and specify the configMapKeyRef stanza for the EGRESS_DESTINATION field in the environment stanza: ... env: - name: EGRESS_DESTINATION valueFrom: configMapKeyRef: name: egress-routes key: destination ... 27.11.2. Additional resources Redirect mode HTTP proxy mode DNS proxy mode 27.12. Enabling multicast for a project Note OpenShift SDN CNI is deprecated as of OpenShift Container Platform 4.14. As of OpenShift Container Platform 4.15, the network plugin is not an option for new installations. In a subsequent future release, the OpenShift SDN network plugin is planned to be removed and no longer supported. Red Hat will provide bug fixes and support for this feature until it is removed, but this feature will no longer receive enhancements. As an alternative to OpenShift SDN CNI, you can use OVN Kubernetes CNI instead. 27.12.1. About multicast With IP multicast, data is broadcast to many IP addresses simultaneously. Important At this time, multicast is best used for low-bandwidth coordination or service discovery and not a high-bandwidth solution. By default, network policies affect all connections in a namespace. However, multicast is unaffected by network policies. If multicast is enabled in the same namespace as your network policies, it is always allowed, even if there is a deny-all network policy. Cluster administrators should consider the implications to the exemption of multicast from network policies before enabling it. Multicast traffic between OpenShift Container Platform pods is disabled by default. If you are using the OpenShift SDN network plugin, you can enable multicast on a per-project basis. When using the OpenShift SDN network plugin in networkpolicy isolation mode: Multicast packets sent by a pod will be delivered to all other pods in the project, regardless of NetworkPolicy objects. Pods might be able to communicate over multicast even when they cannot communicate over unicast. Multicast packets sent by a pod in one project will never be delivered to pods in any other project, even if there are NetworkPolicy objects that allow communication between the projects. When using the OpenShift SDN network plugin in multitenant isolation mode: Multicast packets sent by a pod will be delivered to all other pods in the project. Multicast packets sent by a pod in one project will be delivered to pods in other projects only if each project is joined together and multicast is enabled in each joined project. 27.12.2. Enabling multicast between pods You can enable multicast between pods for your project. Prerequisites Install the OpenShift CLI ( oc ). You must log in to the cluster with a user that has the cluster-admin role. Procedure Run the following command to enable multicast for a project. Replace <namespace> with the namespace for the project you want to enable multicast for. USD oc annotate netnamespace <namespace> \ netnamespace.network.openshift.io/multicast-enabled=true Verification To verify that multicast is enabled for a project, complete the following procedure: Change your current project to the project that you enabled multicast for. Replace <project> with the project name. USD oc project <project> Create a pod to act as a multicast receiver: USD cat <<EOF| oc create -f - apiVersion: v1 kind: Pod metadata: name: mlistener labels: app: multicast-verify spec: containers: - name: mlistener image: registry.access.redhat.com/ubi9 command: ["/bin/sh", "-c"] args: ["dnf -y install socat hostname && sleep inf"] ports: - containerPort: 30102 name: mlistener protocol: UDP EOF Create a pod to act as a multicast sender: USD cat <<EOF| oc create -f - apiVersion: v1 kind: Pod metadata: name: msender labels: app: multicast-verify spec: containers: - name: msender image: registry.access.redhat.com/ubi9 command: ["/bin/sh", "-c"] args: ["dnf -y install socat && sleep inf"] EOF In a new terminal window or tab, start the multicast listener. Get the IP address for the Pod: USD POD_IP=USD(oc get pods mlistener -o jsonpath='{.status.podIP}') Start the multicast listener by entering the following command: USD oc exec mlistener -i -t -- \ socat UDP4-RECVFROM:30102,ip-add-membership=224.1.0.1:USDPOD_IP,fork EXEC:hostname Start the multicast transmitter. Get the pod network IP address range: USD CIDR=USD(oc get Network.config.openshift.io cluster \ -o jsonpath='{.status.clusterNetwork[0].cidr}') To send a multicast message, enter the following command: USD oc exec msender -i -t -- \ /bin/bash -c "echo | socat STDIO UDP4-DATAGRAM:224.1.0.1:30102,range=USDCIDR,ip-multicast-ttl=64" If multicast is working, the command returns the following output: mlistener 27.13. Disabling multicast for a project 27.13.1. Disabling multicast between pods You can disable multicast between pods for your project. Prerequisites Install the OpenShift CLI ( oc ). You must log in to the cluster with a user that has the cluster-admin role. Procedure Disable multicast by running the following command: USD oc annotate netnamespace <namespace> \ 1 netnamespace.network.openshift.io/multicast-enabled- 1 The namespace for the project you want to disable multicast for. 27.14. Configuring network isolation using OpenShift SDN Note OpenShift SDN CNI is deprecated as of OpenShift Container Platform 4.14. As of OpenShift Container Platform 4.15, the network plugin is not an option for new installations. In a subsequent future release, the OpenShift SDN network plugin is planned to be removed and no longer supported. Red Hat will provide bug fixes and support for this feature until it is removed, but this feature will no longer receive enhancements. As an alternative to OpenShift SDN CNI, you can use OVN Kubernetes CNI instead. When your cluster is configured to use the multitenant isolation mode for the OpenShift SDN network plugin, each project is isolated by default. Network traffic is not allowed between pods or services in different projects in multitenant isolation mode. You can change the behavior of multitenant isolation for a project in two ways: You can join one or more projects, allowing network traffic between pods and services in different projects. You can disable network isolation for a project. It will be globally accessible, accepting network traffic from pods and services in all other projects. A globally accessible project can access pods and services in all other projects. 27.14.1. Prerequisites You must have a cluster configured to use the OpenShift SDN network plugin in multitenant isolation mode. 27.14.2. Joining projects You can join two or more projects to allow network traffic between pods and services in different projects. Prerequisites Install the OpenShift CLI ( oc ). You must log in to the cluster with a user that has the cluster-admin role. Procedure Use the following command to join projects to an existing project network: USD oc adm pod-network join-projects --to=<project1> <project2> <project3> Alternatively, instead of specifying specific project names, you can use the --selector=<project_selector> option to specify projects based upon an associated label. Optional: Run the following command to view the pod networks that you have joined together: USD oc get netnamespaces Projects in the same pod-network have the same network ID in the NETID column. 27.14.3. Isolating a project You can isolate a project so that pods and services in other projects cannot access its pods and services. Prerequisites Install the OpenShift CLI ( oc ). You must log in to the cluster with a user that has the cluster-admin role. Procedure To isolate the projects in the cluster, run the following command: USD oc adm pod-network isolate-projects <project1> <project2> Alternatively, instead of specifying specific project names, you can use the --selector=<project_selector> option to specify projects based upon an associated label. 27.14.4. Disabling network isolation for a project You can disable network isolation for a project. Prerequisites Install the OpenShift CLI ( oc ). You must log in to the cluster with a user that has the cluster-admin role. Procedure Run the following command for the project: USD oc adm pod-network make-projects-global <project1> <project2> Alternatively, instead of specifying specific project names, you can use the --selector=<project_selector> option to specify projects based upon an associated label. 27.15. Configuring kube-proxy The Kubernetes network proxy (kube-proxy) runs on each node and is managed by the Cluster Network Operator (CNO). kube-proxy maintains network rules for forwarding connections for endpoints associated with services. 27.15.1. About iptables rules synchronization The synchronization period determines how frequently the Kubernetes network proxy (kube-proxy) syncs the iptables rules on a node. A sync begins when either of the following events occurs: An event occurs, such as service or endpoint is added to or removed from the cluster. The time since the last sync exceeds the sync period defined for kube-proxy. 27.15.2. kube-proxy configuration parameters You can modify the following kubeProxyConfig parameters. Note Because of performance improvements introduced in OpenShift Container Platform 4.3 and greater, adjusting the iptablesSyncPeriod parameter is no longer necessary. Table 27.2. Parameters Parameter Description Values Default iptablesSyncPeriod The refresh period for iptables rules. A time interval, such as 30s or 2m . Valid suffixes include s , m , and h and are described in the Go time package documentation. 30s proxyArguments.iptables-min-sync-period The minimum duration before refreshing iptables rules. This parameter ensures that the refresh does not happen too frequently. By default, a refresh starts as soon as a change that affects iptables rules occurs. A time interval, such as 30s or 2m . Valid suffixes include s , m , and h and are described in the Go time package 0s 27.15.3. Modifying the kube-proxy configuration You can modify the Kubernetes network proxy configuration for your cluster. Prerequisites Install the OpenShift CLI ( oc ). Log in to a running cluster with the cluster-admin role. Procedure Edit the Network.operator.openshift.io custom resource (CR) by running the following command: USD oc edit network.operator.openshift.io cluster Modify the kubeProxyConfig parameter in the CR with your changes to the kube-proxy configuration, such as in the following example CR: apiVersion: operator.openshift.io/v1 kind: Network metadata: name: cluster spec: kubeProxyConfig: iptablesSyncPeriod: 30s proxyArguments: iptables-min-sync-period: ["30s"] Save the file and exit the text editor. The syntax is validated by the oc command when you save the file and exit the editor. If your modifications contain a syntax error, the editor opens the file and displays an error message. Enter the following command to confirm the configuration update: USD oc get networks.operator.openshift.io -o yaml Example output apiVersion: v1 items: - apiVersion: operator.openshift.io/v1 kind: Network metadata: name: cluster spec: clusterNetwork: - cidr: 10.128.0.0/14 hostPrefix: 23 defaultNetwork: type: OpenShiftSDN kubeProxyConfig: iptablesSyncPeriod: 30s proxyArguments: iptables-min-sync-period: - 30s serviceNetwork: - 172.30.0.0/16 status: {} kind: List Optional: Enter the following command to confirm that the Cluster Network Operator accepted the configuration change: USD oc get clusteroperator network Example output NAME VERSION AVAILABLE PROGRESSING DEGRADED SINCE network 4.1.0-0.9 True False False 1m The AVAILABLE field is True when the configuration update is applied successfully.

Commands:
IP capacity = public cloud default capacity - sum(current IP assignments)
cloud.network.openshift.io/egress-ipconfig: [ { "interface":"eni-078d267045138e436", "ifaddr":{"ipv4":"10.0.128.0/18"}, "capacity":{"ipv4":14,"ipv6":15} } ]
cloud.network.openshift.io/egress-ipconfig: [ { "interface":"nic0", "ifaddr":{"ipv4":"10.0.128.0/18"}, "capacity":{"ip":14} } ]
oc patch netnamespace <project_name> --type=merge -p '{ "egressIPs": [ "<ip_address>" ] }'
oc patch netnamespace project1 --type=merge -p '{"egressIPs": ["192.168.1.100"]}' oc patch netnamespace project2 --type=merge -p '{"egressIPs": ["192.168.1.101"]}'
oc patch hostsubnet <node_name> --type=merge -p '{ "egressCIDRs": [ "<ip_address_range>", "<ip_address_range>" ] }'
oc patch hostsubnet node1 --type=merge -p '{"egressCIDRs": ["192.168.1.0/24"]}' oc patch hostsubnet node2 --type=merge -p '{"egressCIDRs": ["192.168.1.0/24"]}'
oc patch netnamespace <project_name> --type=merge -p '{ "egressIPs": [ "<ip_address>" ] }'
oc patch netnamespace project1 --type=merge -p '{"egressIPs": ["192.168.1.100","192.168.1.101"]}'
oc patch hostsubnet <node_name> --type=merge -p '{ "egressIPs": [ "<ip_address>", "<ip_address>" ] }'
oc patch hostsubnet node1 --type=merge -p '{"egressIPs": ["192.168.1.100", "192.168.1.101", "192.168.1.102"]}'
apiVersion: network.openshift.io/v1 kind: EgressNetworkPolicy metadata: name: default namespace: <namespace> 1 spec: egress: - to: cidrSelector: <api_server_address_range> 2 type: Allow - to: cidrSelector: 0.0.0.0/0 3 type: Deny
apiVersion: network.openshift.io/v1 kind: EgressNetworkPolicy metadata: name: <name> 1 spec: egress: 2
egress: - type: <type> 1 to: 2 cidrSelector: <cidr> 3 dnsName: <dns_name> 4
apiVersion: network.openshift.io/v1 kind: EgressNetworkPolicy metadata: name: default spec: egress: 1 - type: Allow to: cidrSelector: 1.2.3.0/24 - type: Allow to: dnsName: www.example.com - type: Deny to: cidrSelector: 0.0.0.0/0
oc create -f <policy_name>.yaml -n <project>
oc create -f default.yaml -n project1
egressnetworkpolicy.network.openshift.io/v1 created
oc get egressnetworkpolicy --all-namespaces
oc describe egressnetworkpolicy <policy_name>
Name: default Namespace: project1 Created: 20 minutes ago Labels: <none> Annotations: <none> Rule: Allow to 1.2.3.0/24 Rule: Allow to www.example.com Rule: Deny to 0.0.0.0/0
oc get -n <project> egressnetworkpolicy
oc get -n <project> egressnetworkpolicy <name> -o yaml > <filename>.yaml
oc replace -f <filename>.yaml
oc get -n <project> egressnetworkpolicy
oc delete -n <project> egressnetworkpolicy <name>
curl <router_service_IP> <port>
openstack port set --allowed-address ip_address=<ip_address>,mac_address=<mac_address> <neutron_port_uuid>
apiVersion: apps/v1 kind: Deployment metadata: name: egress-demo-controller spec: replicas: 1 1 selector: matchLabels: name: egress-router template: metadata: name: egress-router labels: name: egress-router annotations: pod.network.openshift.io/assign-macvlan: "true" spec: 2 initContainers: containers:
apiVersion: v1 kind: Pod metadata: name: egress-1 labels: name: egress-1 annotations: pod.network.openshift.io/assign-macvlan: "true" 1 spec: initContainers: - name: egress-router image: registry.redhat.io/openshift4/ose-egress-router securityContext: privileged: true env: - name: EGRESS_SOURCE 2 value: <egress_router> - name: EGRESS_GATEWAY 3 value: <egress_gateway> - name: EGRESS_DESTINATION 4 value: <egress_destination> - name: EGRESS_ROUTER_MODE value: init containers: - name: egress-router-wait image: registry.redhat.io/openshift4/ose-pod
apiVersion: v1 kind: Pod metadata: name: egress-multi labels: name: egress-multi annotations: pod.network.openshift.io/assign-macvlan: "true" spec: initContainers: - name: egress-router image: registry.redhat.io/openshift4/ose-egress-router securityContext: privileged: true env: - name: EGRESS_SOURCE value: 192.168.12.99/24 - name: EGRESS_GATEWAY value: 192.168.12.1 - name: EGRESS_DESTINATION value: | 80 tcp 203.0.113.25 8080 tcp 203.0.113.26 80 8443 tcp 203.0.113.26 443 203.0.113.27 - name: EGRESS_ROUTER_MODE value: init containers: - name: egress-router-wait image: registry.redhat.io/openshift4/ose-pod
80 tcp 203.0.113.25 8080 tcp 203.0.113.26 80 8443 tcp 203.0.113.26 443 203.0.113.27
curl <router_service_IP> <port>
apiVersion: v1 kind: Service metadata: name: egress-1 spec: ports: - name: http port: 80 - name: https port: 443 type: ClusterIP selector: name: egress-1
apiVersion: v1 kind: Pod metadata: name: egress-1 labels: name: egress-1 annotations: pod.network.openshift.io/assign-macvlan: "true" 1 spec: initContainers: - name: egress-router image: registry.redhat.io/openshift4/ose-egress-router securityContext: privileged: true env: - name: EGRESS_SOURCE 2 value: <egress-router> - name: EGRESS_GATEWAY 3 value: <egress-gateway> - name: EGRESS_ROUTER_MODE value: http-proxy containers: - name: egress-router-pod image: registry.redhat.io/openshift4/ose-egress-http-proxy env: - name: EGRESS_HTTP_PROXY_DESTINATION 4 value: |-
!*.example.com !192.168.1.0/24 192.168.2.1 *
apiVersion: v1 kind: Service metadata: name: egress-1 spec: ports: - name: http-proxy port: 8080 1 type: ClusterIP selector: name: egress-1
apiVersion: v1 kind: Pod metadata: name: app-1 labels: name: app-1 spec: containers: env: - name: http_proxy value: http://egress-1:8080/ 1 - name: https_proxy value: http://egress-1:8080/
apiVersion: v1 kind: Pod metadata: name: egress-1 labels: name: egress-1 annotations: pod.network.openshift.io/assign-macvlan: "true" 1 spec: initContainers: - name: egress-router image: registry.redhat.io/openshift4/ose-egress-router securityContext: privileged: true env: - name: EGRESS_SOURCE 2 value: <egress-router> - name: EGRESS_GATEWAY 3 value: <egress-gateway> - name: EGRESS_ROUTER_MODE value: dns-proxy containers: - name: egress-router-pod image: registry.redhat.io/openshift4/ose-egress-dns-proxy securityContext: privileged: true env: - name: EGRESS_DNS_PROXY_DESTINATION 4 value: |- - name: EGRESS_DNS_PROXY_DEBUG 5 value: "1"
80 172.16.12.11 100 example.com
8080 192.168.60.252 80 8443 web.example.com 443
apiVersion: v1 kind: Service metadata: name: egress-dns-svc spec: ports: type: ClusterIP selector: name: egress-dns-proxy
apiVersion: v1 kind: Service metadata: name: egress-dns-svc spec: ports: - name: con1 protocol: TCP port: 80 targetPort: 80 - name: con2 protocol: TCP port: 100 targetPort: 100 type: ClusterIP selector: name: egress-dns-proxy
oc create -f egress-router-service.yaml
Egress routes for Project "Test", version 3 80 tcp 203.0.113.25 8080 tcp 203.0.113.26 80 8443 tcp 203.0.113.26 443 Fallback 203.0.113.27
oc delete configmap egress-routes --ignore-not-found
oc create configmap egress-routes --from-file=destination=my-egress-destination.txt
apiVersion: v1 kind: ConfigMap metadata: name: egress-routes data: destination: | # Egress routes for Project "Test", version 3 80 tcp 203.0.113.25 8080 tcp 203.0.113.26 80 8443 tcp 203.0.113.26 443 # Fallback 203.0.113.27
env: - name: EGRESS_DESTINATION valueFrom: configMapKeyRef: name: egress-routes key: destination
oc annotate netnamespace <namespace> netnamespace.network.openshift.io/multicast-enabled=true
oc project <project>
cat <<EOF| oc create -f - apiVersion: v1 kind: Pod metadata: name: mlistener labels: app: multicast-verify spec: containers: - name: mlistener image: registry.access.redhat.com/ubi9 command: ["/bin/sh", "-c"] args: ["dnf -y install socat hostname && sleep inf"] ports: - containerPort: 30102 name: mlistener protocol: UDP EOF
cat <<EOF| oc create -f - apiVersion: v1 kind: Pod metadata: name: msender labels: app: multicast-verify spec: containers: - name: msender image: registry.access.redhat.com/ubi9 command: ["/bin/sh", "-c"] args: ["dnf -y install socat && sleep inf"] EOF
POD_IP=USD(oc get pods mlistener -o jsonpath='{.status.podIP}')
oc exec mlistener -i -t -- socat UDP4-RECVFROM:30102,ip-add-membership=224.1.0.1:USDPOD_IP,fork EXEC:hostname
CIDR=USD(oc get Network.config.openshift.io cluster -o jsonpath='{.status.clusterNetwork[0].cidr}')
oc exec msender -i -t -- /bin/bash -c "echo | socat STDIO UDP4-DATAGRAM:224.1.0.1:30102,range=USDCIDR,ip-multicast-ttl=64"
mlistener
oc annotate netnamespace <namespace> \ 1 netnamespace.network.openshift.io/multicast-enabled-
oc adm pod-network join-projects --to=<project1> <project2> <project3>
oc get netnamespaces
oc adm pod-network isolate-projects <project1> <project2>
oc adm pod-network make-projects-global <project1> <project2>
oc edit network.operator.openshift.io cluster
apiVersion: operator.openshift.io/v1 kind: Network metadata: name: cluster spec: kubeProxyConfig: iptablesSyncPeriod: 30s proxyArguments: iptables-min-sync-period: ["30s"]
oc get networks.operator.openshift.io -o yaml
apiVersion: v1 items: - apiVersion: operator.openshift.io/v1 kind: Network metadata: name: cluster spec: clusterNetwork: - cidr: 10.128.0.0/14 hostPrefix: 23 defaultNetwork: type: OpenShiftSDN kubeProxyConfig: iptablesSyncPeriod: 30s proxyArguments: iptables-min-sync-period: - 30s serviceNetwork: - 172.30.0.0/16 status: {} kind: List
oc get clusteroperator network
NAME VERSION AVAILABLE PROGRESSING DEGRADED SINCE network 4.1.0-0.9 True False False 1m