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Flow for Tenant Systems

This topic explains how packets are processed in flow sessions on devices that are configured with tenant systems. It describes how the device running tenant systems handles pass-through traffic between tenant systems. This topic also covers self-traffic as self-initiated traffic within a tenant system and self-traffic terminated on another tenant system. Before addressing tenant systems, the topic provides basic information about the SRX Series architecture with respect to packet processing and sessions. Finally, addresses the sessions and how to change session characteristics.

Session Creation for Devices Running Tenant Systems

A session is created, based on routing and other classification information, to store information and allocate resources for a flow. Basically, a session is established when a traffic enters a tenant system interface, route lookup is performed to identify the next hop interface, and policy lookup is performed.

Optionally, the tenant systems enable you to configure an internal software switch. A virtual private LAN switch (VPLS) is implemented as an interconnect in tenant system. The VPLS enables both transit traffic and traffic terminated at a tenant system to pass between tenant systems. To allow traffic to pass between tenant systems or between tenant system and logical system, logical tunnel (lt-0/0/0) interfaces across the interconnect tenant system are used.

Note:

Packet sequence occurs at the ingress and the egress interfaces. Packets traversing between tenant systems might not be processed in the order in which they were received on the physical interface.

Understanding Packet Classification

The Packet classification for a flow-based processing is based on both the physical interface and the logical interface and depends on the incoming interface. The packet classification is performed at the ingress point and within a flow, the packet-based processing also takes place on an SPU sometimes.

Packet classification is assessed the same way for devices that are configured with or without tenant systems. The traffic for a dedicated interface is classified to the tenant system that contains that interface. The filters and class-of-service features are typically associated with an interface to influence which packets are allowed to transit the device and to apply special actions to packets as needed.

Understanding the VPLS Switch and Logical Tunnel Interfaces

This topic covers the interconnect tenant system that serves as an internal virtual private LAN service (VPLS) switch connecting one tenant system on the device to another. The topic also explains how logical tunnel (lt-0/0/0) interfaces are used to connect tenant systems through the interconnect tenant system.

A device running tenant systems can use an internal VPLS switch to pass traffic without it leaving the device. For communication between tenant systems on the device to occur, you must configure an lt-0/0/0 interface on each tenant system that will use the internal switch, and you must associate it with its peer lt-0/0/0 interface on the interconnect tenant system, effectively creating a logical tunnel between them. You define a peer relationship at each end of the tunnel when you configure the tenant system’s lt-0/0/0 interfaces.

You might want all tenant systems on the device to be able to communicate with one another without using an external switch. Alternatively, you might want some tenant systems to connect across the internal switch but not all of them.

Warning:

If you configure an lt-0/0/0 interface in any tenant system and you do not configure a VPLS switch containing a peer lt-0/0/0 interface for it, the commit will fail.

An SRX Series device running tenant systems can be used in a chassis cluster and each node has the same configuration.

When you use SRX Series devices configured with tenant systems within a chassis cluster, you must purchase and install the same number of licenses for each node in the chassis cluster. tenant systems licenses pertain to a single chassis, or node, within a chassis cluster and not to the cluster collectively.

Handling Pass-Through Traffic for Tenant Systems

For SRX Series devices running tenant systems, pass-through traffic can exist within a tenant system or between tenant systems.

Pass-Through Traffic Between Tenant Systems

Pass-through traffic between tenant systems is complicated by fact that each tenant system has an ingress and an egress interface that the traffic must transit. It is as if traffic were coming into and going out from two devices. Consider how pass-through traffic is handled between tenant systems given in the topology shown in Figure 1.

Figure 1: Tenant Systems, Their Virtual Routers, and Their InterfacesTenant Systems, Their Virtual Routers, and Their Interfaces

Two sessions must be established for pass-through traffic between tenant systems. (Note that policy lookup is performed in both tenant systems).

  • On the incoming tenant system, one session is set up between the ingress interface (a physical interface) and its egress interface (an lt-0/0/0 interface).

  • On the egress tenant system, another session is set up between the ingress interface (the lt-0/0/0 interface of the second tenant system) and its egress interface (a physical interface).

Consider how pass-through traffic is handled across tenant systems in the topology shown in Figure 1.

  • A session is established in the incoming tenant system.

    • When a packet arrives on interface ge-0/0/5, it is identified as belonging to the tenant-product-design tenant system.

    • Because ge-0/0/5 belongs to the pd-vr1 routing instance, route lookup is performed in pd-vr1.

    • As a result of the lookup, the egress interface for the packet is identified as lt-0/0/0.3 with the next hop identified as lt-0/0/0.5, which is the ingress interface in the tenant-marketing-dept.

    • A session is established between ge-0/0/5 and lt-0/0/0.3.

  • A session is established in the outgoing tenant system.

    • The packet is injected into the flow again from lt-0/0/0.5, and the tenant system context identified as tenant-marketing-dept is derived from the interface.

    • Packet processing continues in the tenant-marketing-dept tenant system.

    • To identify the egress interface, route lookup for the packet is performed in the mk-vr1 routing instances.

    • The outgoing interface is identified as ge-0/0/6, and the packet is transmitted from the interface to the network.

Handling Self-Traffic

Self-traffic is traffic that originates in a tenant system on a device and is either sent out to the network from that tenant system or is terminated on another tenant system on the device.

Self-Initiated Traffic

Self-initiated traffic is generated from a source tenant system context and forwarded directly to the network from the tenant system interface.

The following process occurs:

  • When a packet is generated in a tenant system, a process for handling the traffic is started in the tenant system.

  • Route lookup is performed to identify the egress interface, and a session is established.

  • The tenant system performs a policy lookup and processes the traffic accordingly.

Consider how self-initiated traffic is handled across tenant systems given the topology shown in Figure 1.

  • A packet is generated in the tenant-product-design tenant system, and a process for handling the traffic is started in the tenant system.

  • Route lookup is performed in pd-vr2, and the egress interface is identified as ge-0/0/8.

  • A session is established.

  • The packet is transmitted to the network from ge-0/0/8.

Traffic Terminated on a Tenant System

When a packet enters the device on an interface belonging to a tenant system and the packet is destined for another tenant system on the device, the packet is forwarded between the tenant systems in the same manner as is pass-through traffic. However, route lookup in the second tenant system identifies the local egress interface as the packet destination. Consequently the packet is terminated on the second tenant system as self-traffic.

  • For terminated self-traffic, two policy lookups are performed, and two sessions are established.

    • On the incoming tenant system, one session is set up between the ingress interface (a physical interface) and its egress interface (an lt-0/0/0 interface).

    • On the destination tenant system, another session is set up between the ingress interface (the lt-0/0/0 interface of the second tenant system) and the local interface.

Consider how terminated self-traffic is handled across tenant systems in the topology shown in Figure 1.

  • A session is established in the incoming tenant system.

    • When a packet arrives on interface ge-0/0/5, it is identified as belonging to the tenant-product-design tenant system.

    • Because ge-0/0/5 belongs to the pd-vr1 routing instance, route lookup is performed in pd-vr1.

    • As a result of the lookup, the egress interface for the packet is identified as lt-0/0/0.3 with the next hop identified as lt-0/0/0.5, the ingress interface in the ls-marketing-dept.

    • A session is established between ge-0/0/5 and lt-0/0/0.3.

  • A management session is established in the destination tenant system.

    • The packet is injected into the flow again from lt-0/0/0.5, and the tenant system context identified as tenant-marketing-dept is derived from the interface.

    • Packet processing continues in the tenant-marketing-dept tenant system.

    • Route lookup for the packet is performed in the mk-vr1 routing instance. The packet is terminated in the destination tenant system as self-traffic.

Understanding Session and Gate Limitation Control

Sessions are created based on routing and other classification information to store information and allocate resources for a flow. The tenant systems flow module provides session and gate limitation to ensure that these resources are shared among the tenant systems. Resources allocation and limitations for each tenant system are specified in the security profile bound to the tenant system.

  • For session limiting, the system checks the first packet of a session against the maximum number of sessions configured for the tenant system. When the maximum limit of session is reached, the device drops the packet and logs the event.

  • For gate limiting, the device checks the first packet of a session against the maximum number of gates configured for the tenant system. If the maximum number of gates for a tenant system is reached, the device rejects the gate open request and logs the event.

About Configuring Sessions

Depending on the protocol and service, a session is programmed with a timeout value. For example, the default timeout for TCP is 1800 seconds. The default timeout for UDP is 60 seconds. When a flow is terminated, it is marked as invalid, and its timeout is reduced to 10 seconds. If no traffic uses the If no traffic uses the session before the service timeout, the session is aged out and freed to a common resource pool for reuse.

You can affect the life of a session in the following ways:

  • Age out sessions, based on how full the session table is.

  • Set an explicit timeout for aging out TCP sessions.

  • Configure a TCP session to be invalidated when it receives a TCP RST (reset) message.

  • You can configure sessions to accommodate other systems as follows:

    • Disable TCP packet security checks.

    • Change the maximum segment size.

Configuring Logical Systems and Tenant Systems Interconnect with Multiple VPLS Switches

This example shows how to interconnect logical systems and tenant systems with multiple VPLS switches. This is achieved by configuring multiple logical systems and tenant systems with more than one logical tunnel (LT) interface under a tenant system and multiple VPLS switches that are configured to pass the traffic without leaving an SRX Series device.

Requirements

This example uses an SRX Series device running Junos OS with logical systems and tenant systems.

Overview

In this example, we configure multiple LT interfaces and multiple VPLS switches under one tenant system.

In this example, we also configure interconnection between multiple logical systems and tenant systems with LT interface point-to point connections (Encapsulation Ethernet and Encapsulation Frame-Relay).

For interconnected logical systems and tenant systems with multiple VPLS switches, this example configures logical tunnel interfaces lt-0/0/0 with ethernet-vpls as the encapsulation type. The corresponding peer lt-0/0/0 interfaces and security-profiles are assigned to the logical systems and tenant systems. The routing instance for the VPLS switch-1 and VPLS switch-2 are also assigned to the logical systems and tenant systems.

Figure 2 shows the topology for interconnected logical systems and tenant systems with multiple VPLS switches.

Figure 2: Configuring the interconnected logical systems and tenant systems with multiple VPLS switches.Configuring the interconnected logical systems and tenant systems with multiple VPLS switches.

Configuration

To configure interfaces for the logical system and tenant system, perform these tasks:

CLI Quick Configuration

To quickly configure this example, copy the following commands, paste them into a text file, remove any line breaks, change any details necessary to match your network configuration, copy and paste the commands into the CLI at the [edit] hierarchy level, and then enter commit from configuration mode.

Procedure

Step-by-Step Procedure

The following example requires you to navigate various levels in the configuration hierarchy. For instructions on how to do that, see Using the CLI Editor in Configuration Mode.

  1. Configure the lt-0/0/0 interfaces.

  2. Configure the routing instance for the VPLS switches and add interfaces to it.

  3. Configure LSYS1 with lt-0/0/0.1 interface and peer lt-0/0/0.11.

  4. Configure TSYS1 with lt-0/0/0.2 interface and peer lt-0/0/0.12.

  5. Configure TSYS2 with lt-0/0/0.3 interface and peer lt-0/0/0.13

  6. Configure LSYS2 with lt-0/0/0 interface and peer-unit 24.

  7. Assign security-profile for logical-systems.

Results
  • From configuration mode, confirm your configuration by entering the show interfaces lt-0/0/0, command. If the output does not display the intended configuration, repeat the configuration instructions in this example to correct it

  • From configuration mode, confirm your configuration by entering the show routing-instances, command. If the output does not display the intended configuration, repeat the configuration instructions in this example to correct it.

  • From configuration mode, confirm your configuration by entering the show logical-systems LSYS1, command. If the output does not display the intended configuration, repeat the configuration instructions in this example to correct it.

  • From configuration mode, confirm your configuration by entering the show logical-systems LSYS2, command. If the output does not display the intended configuration, repeat the configuration instructions in this example to correct it.

  • From configuration mode, confirm your configuration by entering the show logical-systems LSYS3, command. If the output does not display the intended configuration, repeat the configuration instructions in this example to correct it.

  • From configuration mode, confirm your configuration by entering the show logical-systems LSYS2, command. If the output does not display the intended configuration, repeat the configuration instructions in this example to correct it.

  • From configuration mode, confirm your configuration by entering the show system security-profile, command. If the output does not display the intended configuration, repeat the configuration instructions in this example to correct it.

If you are done configuring the device, enter commit from configuration mode.

Verification

To confirm that the configuration is working properly, perform these tasks:

Verifying the Security-Profile for Logical-systems

Purpose

Verify security profile for each logical systems.

Action

From operational mode, enter the show system security-profile security-log-stream-number logical-system all command.

Meaning

The output provides the usage and reserved values for the logical systems when security-log-stream is configured.

Verifying the LT Interfaces for Logical systems

Purpose

Verify interfaces for logical systems.

Action

From operational mode, enter the show interfaces lt-0/0/0 terse command.

Meaning

The output provides the status of LT interfaces. All the LT interfaces are up.

Configuring tenant systems Interconnect with Logical Tunnel Interface point-to-point connection

This example shows how to interconnect tenant systems with logical tunnel (LT) interfaces in a point-to-point connection.

Requirements

This example uses an SRX Series device running Junos OS with logical systems and tenant systems.

Overview

In this example we show how to interconnect tenant systems with logical tunnel (LT) interface in a point-to-point connection.

For the interconnected tenant systems with a point-to-point connection (encapsulation frame-relay) LT interface, this example configures the logical tunnel interface lt-0/0/0. This example configures security-zone and assigns interfaces to the logical systems.

The interconnected logical system lt-0/0/0 interface is configured with frame-relay as the encapsulation type. The corresponding peer lt-0/0/0 interfaces in the tenant systems are configured with frame-relay as the encapsulation type. A security profile is assigned to the tenant systems.

Figure 3 shows the topology for interconnected tenant systems with a point-to-point connection LT interface.

Figure 3: Configuring the interconnect tenant systems with a point-to-point connection LT interfaceConfiguring the interconnect tenant systems with a point-to-point connection LT interface

Configuration

To configure security-zone and assigns interfaces to tenant systems, perform these tasks:

CLI Quick Configuration

To quickly configure this example, copy the following commands, paste them into a text file, remove any line breaks, change any details necessary to match your network configuration, copy and paste the commands into the CLI at the [edit] hierarchy level, and then enter commit from configuration mode.

Configuring [item]

Step-by-Step Procedure

The following example requires you to navigate various levels in the configuration hierarchy. For instructions on how to do that, see Using the CLI Editor in Configuration Mode.

  1. Define a security profile sp1 and assign to a tenant system TNI. Define another security profile sp1 and assign to a tenant system TSYS1A

  2. Set the interface for reth0 and reth1 and assign it to the redundancy group 1 and redundancy group 2.

  3. Set the LT interface as encapsulation ethernet in the tenant system TSYS1.

  4. Configure a peer unit relationship between LT interfaces, thus creating a point-to-point connection.

  5. Specify the IP address for the LT interface.

  6. Specify the IP address for the reth0.

  7. Set the LT interface as encapsulation ethernet in the tenant system TSYS1A.

  8. Configure a peer unit relationship between LT interfaces, thus creating a point-to-point connection.

  9. Specify the IP address for the LT interface.

  10. Specify the IP address for the reth1.

  11. Define the routing-instances for TSYS1.

  12. Configure a security policy that permits all traffics.

  13. Configure security zones.

  14. Define the routing-instances for TSYS1A.

  15. Configure a security policy that permits all traffics.

  16. Configure security zones.

Results

  • From configuration mode, confirm your configuration by entering the show tenants TSYS1 commands. If the output does not display the intended configuration, repeat the configuration instructions in this example to correct it.

  • From configuration mode, confirm your configuration by entering the show tenants TSYS1A commands. If the output does not display the intended configuration, repeat the configuration instructions in this example to correct it.

If you are done configuring the device, enter commit from configuration mode.

Verification

To confirm that the configuration is working properly, perform these tasks:

Verifying the Security-Profile for all tenant systems

Purpose

Verify security profile for each logical systems.

Action

From operational mode, enter the show system security-profile zone tenant al command.

Meaning

The output provides the usage and reserved values for the logical systems when security-log-stream is configured.

Configuring Logical System and Tenant System Interconnect with a Logical Tunnel Interface point-to-point connection

This example shows how to interconnect logical systems and tenant systems with logical tunnel (LT) interface in a point-to-point connection.

Requirements

This example uses an SRX Series device running Junos OS with logical systems and tenant systems.

Overview

In this example we show how to interconnect logical systems and tenant systems with logical tunnel (LT) interface point-to-point connection.

For the interconnect logical system and tenant system with a point-to-point connection LT interface, the example configures logical tunnel interfaces lt-0/0/0. This example configures security-zone and assigns interfaces to the logical systems

To interconnect the logical system and tenant system, lt-0/0/0 interfaces are configured with Ethernet as the encapsulation type. The corresponding peer lt-0/0/0 interfaces are configured with Ethernet as the encapsulation type. A security profile is assigned to the logical system and tenant system

Figure 4 shows the topology for interconnected logical systems and tenant systems with LT interface point-to-point connection.

Figure 4: Configuring the interconnect between logical systems and tenant systems with a point-to-point connection LT interfaceConfiguring the interconnect between logical systems and tenant systems with a point-to-point connection LT interface

Configuration

To configure security-zone and assigns interfaces to logical systems, perform these tasks:

CLI Quick Configuration

To quickly configure this example, copy the following commands, paste them into a text file, remove any line breaks, change any details necessary to match your network configuration, copy and paste the commands into the CLI at the [edit] hierarchy level, and then enter commit from configuration mode.

Procedure

Step-by-Step Procedure

The following example requires you to navigate various levels in the configuration hierarchy. For instructions on how to do that, see Using the CLI Editor in Configuration Mode in the Junos OS CLI User Guide.

  1. Define a security profile and assign to a tenant system.

  2. Set the LT interface as encapsulation ethernet in the tenant system.

  3. Configure a peer relationship for tenant systems TSYS2.

  4. Specify the IP address for the LT interface.

  5. Set the security zone for the LT interface.

  6. Define a security profile and assign to a logical system.

  7. Define the routing-instances for TSYS2.

  8. Set the LT interface as encapsulation ethernet in the logical system 3A.

  9. Configure a peer relationship for logical systems LSYS3A.

  10. Specify the IP address for the LT interface.

  11. Configure a security policy that permits traffic from the LT zone to the LT policy LT zone.

  12. Configure a security policy that permits traffic from default-policy.

  13. Configure security zones.

Results

  • From configuration mode, confirm your configuration by entering the show tenants TSYS2 command. If the output does not display the intended configuration, repeat the configuration instructions in this example to correct it.

  • From configuration mode, confirm your configuration by entering the show logical-systems LSYS3A command. If the output does not display the intended configuration, repeat the configuration instructions in this example to correct it.

If you are done configuring the device, enter commit from configuration mode.

Verification

To confirm that the configuration is working properly, perform these tasks:

Verifying the LT Interfaces for all Logical and tenant systems

Purpose

Verify interfaces for logical systems.

Action

From operational mode, enter the show system security-profile zone all-logical-systems-tenants command.

Meaning

The output provides the status of LT interfaces. All the LT interfaces are up.

Verifying the Security-Profile for all Logical-systems

Purpose

Verify security profile for each logical systems.

Action

From operational mode, enter the show system security-profile security-log-stream-number logical-system all command.

Meaning

The output provides the usage and reserved values for the logical systems when security-log-stream is configured.