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Configuring IP Monitoring

 
Summary

This section describes how to keep track of the status of the system in use.

IP Monitoring Overview

This feature monitors IP on standalone SRX Series devices or a chassis cluster redundant Ethernet (reth) interface. Existing RPM probes are sent to an IP address to check for reachability. The user takes action based on the reachability result. Supported action currently is preferred static route injection to system route table.

The actions supported are:

  • Adding or deleting a new static route that has a higher priority (lower preference) value than a route configured through the CLI command set routing-options static route

  • Defining multiple probe names under the same IP monitoring policy. If any probe fails, the action is taken. If all probes are reachable, the action is reverted

  • Configuring multiple tests in one RPM probe. All tests must fail for the RPM probe to be considered unreachable. If at least one test reaches its target, the RPM probe is considered reachable

  • Configuring multiple failure thresholds in one RPM test. If one threshold is reached, the test fails. If no thresholds are reached, the test succeeds.

  • Specifying the no-preempt option. If the no-preempt option is specified, the policy does not perform preemptive failback when it is in a failover state or when the RPM probe test recovers from a failure.

  • Setting preferred metric values. If the preferred metric value is set, during failover, the route is injected with the set preferred metric value.

  • Enabling and disabling interfaces.

    • Interface-Enable—On a physical or logical interface, when the interface-enable action is configured, the initial state of the interface is disable after startup, and it continues to remain in the disable state as long as the associated RPM probe is in the pass state. When the associated RPM probe fails, the configured physical and logical interfaces are enabled.

    • Interface-Disable—On a physical or logical interface, when the interface-disable action is configured, the interface state remains unchanged. When the associated RPM probe fails, the physical and logical interfaces are disabled.

Note

Multiple probe names and actions can be defined for the same IP monitoring policy.

Understanding IP Monitoring Test Parameters

Each probed target is monitored over the course of a test, which represents a collection of probes during which statistics such as standard deviation and jitter are collected are calculated. During a test, probes are generated and responses collected at a rate defined by the probe interval, the number of seconds between probes.

Note

To avoid flap, an action is reverted only at the end of a test cycle. During the test cycle, if no threshold is reached, the action is reverted. Although action-failover takes place based on a predefined condition of a monitored IP, when the condition is reversed, the IP becomes reachable on the original route, and the newly added route is deleted. Recovery is performed only when all RPM probes report the IP as reachable.

Table 1 lists the test parameters and its default values:

Table 1: Test Parameters and Default Values

Parameter

Default Value

probe-count

1

probe-interval

3 seconds

test-interval

1 second

Table 2 lists the supported threshold and its description:

Table 2: Threshold Supported and Description

Threshold

Description

Successive-Loss

Successive loss count of probes

Total-Loss

Total probe lost count

IP monitoring checks the reachability of an upstream device. It is designed to check the end-to-end connectivity of configured IP addresses and allows a redundancy group (RG) to automatically failover when the monitored IP address is not reachable through the redundant Ethernet. Both the primary and secondary devices in the chassis cluster monitor specific IP addresses to determine whether an upstream device in the network is reachable.

A redundant Ethernet interface contains physical interfaces from both the primary and secondary nodes in the SRX Series chassis cluster. In a redundant Ethernet interface, two physical interfaces are configured with each node contributing one physical interface. In a redundant Ethernet interface LAG, more than two physical interfaces are configured in the redundant Ethernet interface.

Example: Configuring IP Monitoring on SRX5000 Series Devices

This example shows how to monitor SRX Series devices with chassis cluster enabled.

Requirements

  • You need two SRX5800 Services Gateways with identical hardware configurations, one SRX Series device and one EX8208 Ethernet Switch.

  • Physically connect the two SRX5800 devices (back-to-back for the fabric and control ports) and ensure that they are the same models. Configure/add these two devices in a cluster.

Overview

IP address monitoring checks end-to-end reachability of configured IP address and allows a redundancy group to automatically fail over when not reachable through the child link of redundant Ethernet interface (known as a reth) interface. Redundancy groups on both devices in a cluster can be configured to monitor specific IP addresses to determine whether an upstream device in the network is reachable.

When you configure multiple IP addresses on the reth Interface in a chassis cluster setup, IP monitoring uses the first IP address from the list of IP addresses configured for that reth interface on the primary node, and the first IP address from the list of secondary IP addresses configured for that reth interface on the backup node. The first IP address is the one with smallest prefix (netmask).

This example shows how to set up IP monitoring on an SRX Series device.

Note

IP monitoring is not supported on an NP-IOC card.

Note

IP monitoring does not support MIC online/offline status on SRX devices.

Topology

Figure 1 shows the topology used in this example.

Figure 1: IP Monitoring on an SRX Series Device Topology Example
IP Monitoring on an SRX Series
Device Topology Example

In this example, two SRX5800 devices in a chassis cluster are connected to an SRX1500 device through an EX8208 Ethernet Switch. The example shows how the redundancy groups can be configured to monitor key upstream resources reachable through redundant Ethernet interfaces on either node in a cluster.

Configuration

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 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.

set chassis cluster reth-count 1
set chassis cluster redundancy-group 0 node 0 priority 254
set chassis cluster redundancy-group 0 node 1 priority 1
set chassis cluster redundancy-group 1 node 0 priority 200
set chassis cluster redundancy-group 1 node 1 priority 199
set chassis cluster redundancy-group 1 ip-monitoring global-weight 255
set chassis cluster redundancy-group 1 ip-monitoring global-threshold 80
set chassis cluster redundancy-group 1 ip-monitoring retry-interval 3
set chassis cluster redundancy-group 1 ip-monitoring retry-count 10
set chassis cluster redundancy-group 1 ip-monitoring family inet 192.0.0.1 weight 80
set chassis cluster redundancy-group 1 ip-monitoring family inet 192.0.0.1 interface reth0.0 secondary-ip-address 192.0.2.2
set interfaces ge-0/0/1 gigether-options redundant-parent reth0
set interfaces ge-4/0/1 gigether-options redundant-parent reth0
set interfaces reth0 redundant-ether-options redundancy-group 1
set interfaces reth0 unit 0 family inet address 192.0.2.1/24
set routing-options static route 192.0.0.1/32 next-hop 192.0.2.3

Configuring IP Monitoring on SRX Series Device

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 .

To configure IP monitoring on an SRX Series device:

  1. Specify the number of redundant Ethernet interfaces.
  2. Specify a redundancy group's priority for primacy on each node of the cluster. The higher number takes precedence.
  3. Configure the redundant Ethernet interfaces to redundancy-group 1.
  4. Assign child interfaces for the redundant Ethernet interfaces from node 0 and node 1.
  5. Configure the static route to the IP address that is to be monitored.
  6. Configure IP monitoring under redundancy-group 1 with global weight and global threshold.
  7. Specify the retry interval.
  8. Specify the retry count.
  9. Assign a weight to the IP address to be monitored, and configure a secondary IP address that will be used to send ICMP packets from the secondary node to track the IP being monitored.
    Note
    • The redundant Ethernet (reth0) IP address, 192.0.2.1/24, is used to send ICMP packets from node 0 to check the reachability of the monitored IP.

    • The secondary IP address, 192.0.2.2, should belong to the same network as the reth0 IP address.

    • The secondary IP address is used to send ICMP packets from node 1 to check the reachability of the monitored IP.

Verification

Confirm the configuration is working properly.

Verifying Chassis Cluster Status— Before Failover

Purpose

Verify the chassis cluster status, failover status, and redundancy group information before failover.

Action

From operational mode, enter the show chassis cluster status command.

show chassis cluster status

Verifying Chassis Cluster IP Monitoring Status— Before Failover

Purpose

Verify the IP status being monitored from both nodes and the failover count for both nodes before failover.

Action

From operational mode, enter the show chassis cluster ip-monitoring status redundancy-group 1 command.

show chassis cluster ip-monitoring status redundancy-group 1

Verifying Chassis Cluster Status— After Failover

Purpose

Verify the chassis cluster status, failover status, and redundancy group information after failover.

Note

If the IP address is not reachable, the following output will be displayed.

Action

From operational mode, enter the show chassis cluster status command.

show chassis cluster status

Verifying Chassis Cluster IP Monitoring Status— After Failover

Purpose

Verify the IP status being monitored from both nodes and the failover count for both nodes after failover.

Action

From operational mode, enter the show chassis cluster ip-monitoring status redundancy-group 1 command.

show chassis cluster ip-monitoring status redundancy-group 1

Example: Configuring IP Monitoring on SRX Series Devices

This example shows how to monitor IP on an SRX Series device.

Requirements

Before you begin:

Configure the following RPM options for RPM test:

  • target-address

  • probe-count

  • probe-interval

  • test-interval

  • thresholds

  • next-hop

Overview

This example shows how to set up IP monitoring on an SRX Series device.

Configuration

CLI Quick Configuration

To quickly configure this example, copy the following commands, past them into a text file, remove any line breaks, change any details 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.

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 .

To configure IP monitoring on an SRX Series Services Gateway:

  1. Configure the target address under the RPM probe.
  2. Configure the probe count under the RPM probe.
  3. Configure the probe interval (in seconds) under the RPM probe.
  4. Configure the test interval (in seconds) under the RPM probe.
  5. Configure the threshold successive loss count under the RPM
  6. Configure the next-hop IP address under the RPM probe.
  7. Configure the IP monitoring policy under services.
    Note

    The following steps are not mandatory. You can configure interface actions and route actions independently, or you can configure both the interface action and the route action together in one IP monitoring policy.

  8. Configure the IP monitoring preferred route under services.
  9. Configure the IP monitoring interface actions.
    • Enable

    • Disable

  10. Configure the no-preempt option.

Verification

Verifying IP Monitoring

Purpose

Verify the IP monitoring status of a policy.

Action

To verify the configuration is working properly, enter the following command:

show services ip-monitoring status <policy-name>

Example: Configuring Chassis Cluster Redundancy Group IP Address Monitoring

This example shows how to configure redundancy group IP address monitoring for an SRX Series device in a chassis cluster.

Requirements

Before you begin:

Overview

You can configure redundancy groups to monitor upstream resources by pinging specific IP addresses that are reachable through redundant Ethernet interfaces on either node in a cluster. You can also configure global threshold, weight, retry interval, and retry count parameters for a redundancy group. When a monitored IP address becomes unreachable, the weight of that monitored IP address is deducted from the redundancy group IP address monitoring global threshold. When the global threshold reaches 0, the global weight is deducted from the redundancy group threshold. The retry interval determines the ping interval for each IP address monitored by the redundancy group. The pings are sent as soon as the configuration is committed. The retry count sets the number of allowed consecutive ping failures for each IP address monitored by the redundancy group.

In this example, you configure the following settings for redundancy group 1:

  • IP address to monitor—10.1.1.10

  • IP address monitoring global-weight—100

  • IP address monitoring global-threshold—200

    The threshold applies cumulatively to all IP addresses monitored by the redundancy group.

  • IP address retry-interval—3 seconds

  • IP address retry-count—10

  • Weight—100

  • Redundant Ethernet interface—reth1.0

  • Secondary IP address—10.1.1.101

Configuration

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.

Step-by-Step Procedure

To configure redundancy group IP address monitoring:

  1. Specify a global monitoring weight.
  2. Specify the global monitoring threshold.
  3. Specify the retry interval.
  4. Specify the retry count.
  5. Specify the IP address to be monitored, weight, redundant Ethernet interface, and secondary IP address.

Results

From configuration mode, confirm your configuration by entering the show chassis cluster redundancy-group 1 command. If the output does not display the intended configuration, repeat the configuration instructions in this example to correct it.

For brevity, this show command output includes only the configuration that is relevant to this example. Any other configuration on the system has been replaced with ellipses (...).

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

Verification

Verifying the Status of Monitored IP Addresses for a Redundancy Group

Purpose

Verify the status of monitored IP addresses for a redundancy group.

Action

From operational mode, enter the show chassis cluster ip-monitoring status command. For information about a specific group, enter the show chassis cluster ip-monitoring status redundancy-group command.

{primary:node0}
user@host> show chassis cluster ip-monitoring status