Manual Chapter : Configuring MQTT Functionality

Applies To:

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BIG-IP LTM

  • 16.1.3, 16.1.2, 16.1.1, 16.1.0, 16.0.1, 16.0.0, 15.1.8, 15.1.7, 15.1.6, 15.1.5, 15.1.4, 15.1.3, 15.1.2, 15.1.1, 15.1.0, 15.0.1, 15.0.0, 14.1.5, 14.1.4, 14.1.3, 14.1.2, 14.1.0, 14.0.1, 14.0.0
Manual Chapter

Configuring MQTT Functionality

Overview: Creating an MQTT configuration

You can use a Message Queuing Telemetry Transport (MQTT) configuration to optimize the performance and bandwidth of mobile environments. Because the MQTT protocol is designed for lightweight publish-and-subscribe messaging, it reduces or eliminates the disadvantages of the commonly used HTTP request-response protocol, especially in mobile environments. For example, you will want to use an MQTT configuration when devices use intermittent connectivity, when bandwidth is at a premium, when an enterprise application interacts with multiple mobile device applications, or when mobile device applications send data reliably without requiring retries.
In an MQTT configuration, clients publish messages, and the BIG-IP system validates and manages those messages through a pool of message brokers, which then transport and route the messages to subscribing servers. You can examine statistics specific to MQTT parameters through the Profiles Summary.
A typical BIG-IP MQTT configuration includes:
  • MQTT pool of message brokers
  • iRules for MQTT
  • Client SSL profile
  • MQTT profile (configured in TMSH)
  • Virtual server configured to use MQTT functionality
An MQTT configuration
Complete these tasks to configure the BIG-IP system to use MQTT functionality.

Task list

Create an MQTT monitor
Create a pool
Create an iRule for MQTT publishing
Create a Client SSL profile
Create a virtual server for MQTT
View MQTT statistics

About the MQTT profile

The Message Queuing Telemetry Transport (MQTT) profile supports MQTT protocol functionality, enabling you to configure a publish-and-subscribe environment to manage devices in an Internet of Things (IoT) context. The BIG-IP system includes a default MQTT profile, configured in TMSH, that you assign to a virtual server.

Example iRule to log MQTT messages

This example iRule shows how to log MQTT messages.
ltm rule mqtt_rule { when MQTT_CLIENT_INGRESS { log local0. "Client message type [MQTT::type]" switch [MQTT::type] { CONNECT { log local0. " protocol-name [MQTT::protocol_name]" log local0. " protocol-version [MQTT::protocol_version]" log local0. " client-id [MQTT::client_id]" log local0. " keep-alive [MQTT::keep_alive]" log local0. " username [MQTT::username]" log local0. " password [MQTT::password]" } PUBLISH { log local0. " qos [MQTT::qos]" log local0. " message-id [MQTT::message_id]" log local0. " topic [MQTT::topic]" } PUBREL { log local0. " message-id [MQTT::message_id]" } SUBSCRIBE { log local0. " message-id [MQTT::message_id]" set count [MQTT::topic count] for {set i 0} {$i < $count} {incr i} { set topic [MQTT::topic index $i] log local0. " topics index $i $topic" log local0. " topics index $i qos [MQTT::message topics qos $topic]" } } UNSUBSCRIBE { log local0. " message-id [MQTT::message_id]" set count [MQTT::topic count] for {set i 0} {$i < $count} {incr i} { log local0. " topics index $i [MQTT::topic index $i]" } } } } when MQTT_SERVER_INGRESS { log local0. "Server message type [MQTT::type]" switch [MQTT::type] { CONNACK { log local0. " return-code [MQTT::return_code]" } PUBLISH { log local0. " message-id [MQTT::message_id]" log local0. " topic [MQTT::topic]" } PUBACK { log local0. " message-id [MQTT::message_id]" } PUBREC { log local0. " message-id [MQTT::message_id]" } PUBCOMP { log local0. " message-id [MQTT::message_id]" } SUBACK { log local0. " message-id [MQTT::message_id]" } UNSUBACK { log local0. " message-id [MQTT::message_id]" } } } }

Example iRule to pass client certificate common name

This example iRule shows how to pass the common name for a client certificate to an MQTT server through the username field in the CONNECT message.
when CLIENT_ACCEPTED { set cn "" } when CLIENTSSL_CLIENTCERT { set cn [ lindex [ split [lindex [ split [X509::subject [SSL::cert 0]] "," ] 0 ] "=" ] 1 ] log local0. "Client Cert Common Name : $cn" } when MQTT_CLIENT_INGRESS { if {[MQTT::type] == "CONNECT"} { if {$cn == ""} { # if we didn't see a client cert, return an authentication error MQTT::drop # drop current message MQTT::respond type CONNACK return-code 5 # send a CONNACK MQTT::disconnect # and disconnect } else { MQTT::username $cn # fill-in username field } } }

Create an MQTT monitor

You can create an MQTT monitor to monitor MQTT brokers that are configured as pool members in an LTM pool.
  1. On the Main tab, click
    Local Traffic
    Monitors
    .
    The Monitors List screen opens.
  2. Click
    Create
    .
    The New Monitor screen opens.
  3. In the
    Name
    field, type a name for the monitor.
  4. From the
    Type
    list, select
    MQTT
    .
    The screen refreshes, and displays the configuration options for the
    MQTT
    monitor type.
  5. From the
    Configuration
    list, select
    Advanced
    .
    This selection makes it possible for you to modify additional default settings.
  6. In the
    Interval
    field, type a number that indicates, in seconds, how frequently the system issues the monitor check.
    The default is
    5
    seconds.
  7. To specify a different interval for health checking, from the
    Up Interval
    list, select
    Enabled
    , and, in the
    Up Interval
    field, type the number of seconds for the interval.
    The default is
    Disabled
    .
  8. In the
    Time Until Up
    field, type the number of seconds to wait after a resource first responds correctly to the monitor before setting the resource to up.
    The default is
    0
    seconds.
  9. In the
    Timeout
    field, type the number of seconds that the target has in which to respond to the monitor request.
    The default is
    16
    seconds.
  10. To specify that you must manually re-enable the resource after an unsuccessful monitor check, for
    Manual Resume
    , select
    Yes
    .
    The default is
    No
    .
  11. From the
    MQTT Version
    list, select the protocol version that the monitor will use to communicate with the monitoring object.
    The default is
    3.1.1
    .
  12. In the
    Client ID
    field, type the Client ID that the monitor will send to communicate with the monitoring object.
  13. If the monitored object requires authentication, type a
    User Name
    .
  14. If the monitored target requires authentication, type a
    Password
    .
  15. In the
    Alias Address
    field, type an alias IP address for the monitor to check, on behalf of the pools or pool members with which the monitor is associated.
    The default is
    * All Addresses
    .
  16. In the
    Alias Service Port
    field, type an alias port or, from the
    Alias Service Port
    list, select a service for the monitor to check, on behalf of the pools or pool members with which the monitor is associated.
    The default is
    * All Ports
    .
  17. Click
    Finished
    .

Create a pool

Before you can assign an MQTT health monitor to a pool, you need to create the MQTT monitor.
You can create a pool of servers that you can group together to receive and process traffic. After the pool is created, you can associate the pool with a virtual server.
  1. On the Main tab, click
    Local Traffic
    Pools
    .
    The Pool List screen opens.
  2. Click
    Create
    .
    The New Pool screen opens.
  3. In the
    Name
    field, type a unique name for the pool.
  4. For the
    Health Monitors
    setting, select an MQTT health monitor from the
    Available
    field, and move it to the
    Active
    field.
  5. For each pool member, in the
    New Members
    setting, select one of the options, and then follow the steps to configure the applicable settings.
    Option
    Steps
    New Node
    1. In the
      Node Name
      field, type a name for the node portion of the pool member.
    2. In the
      Address
      field, type the IP address of the server.
    3. For the
      Service Port
      setting, type one of the following port numbers, or select one of the following services from the list.
      Port Number
      Service Name
      1883
      MQTT
      . The Internet Assigned Numbers Authority (IANA) registered port for MQTT service.
      8883
      MQTT-TLS
      . The IANA registered port for secure MQTT service over a Transport Layer Security (TLS) network.
    4. Click
      Add
      .
    New FQDN Node
    1. In the
      Node Name
      field, type a name for the node portion of the pool member.
    2. In the
      FQDN
      field, type the FQDN of the server.
      To use FQDNs instead of IP addresses, you should still type at least one IP address. Typing one IP address ensures that the system can find a pool member if a DNS server is not available.
    3. For the
      Service Port
      setting, type one of the following port numbers, or select one of the following services from the list.
      Port Number
      Service Name
      1883
      MQTT
      . The Internet Assigned Numbers Authority (IANA) registered port for MQTT service.
      8883
      MQTT-TLS
      . The IANA registered port for secure MQTT service over a Transport Layer Security (TLS) network.
    4. From the
      Auto Populate
      list, select
      Enabled
      to automatically create ephemeral nodes, using the IP addresses returned by the resolution of a DNS query for the pool member defined by the FQDN.
    5. Click
      Add
      .
  6. Click
    Finished
    .
    The screen refreshes, and you see the new pool in the Pool list.

Create an iRule for MQTT publishing

You can create iRules for MQTT functionality, for example to log the messages that the BIG-IP system passes, or to pass the client certificate's common name in the CONNECT message.
  1. On the Main tab, click
    Local Traffic
    iRules
    .
    The iRule List screen opens, displaying any existing iRules.
  2. Click
    Create
    .
    The New iRule screen opens.
  3. In the
    Name
    field, type a unique name for the iRule.
    The full path name of the iRule cannot exceed 255 characters.
  4. In the
    Definition
    field, type an iRule.
  5. Click
    Finished
    .
    The new iRule appears in the list of iRules on the system.
The BIG-IP system includes the iRules for MQTT functionality that you've created.

Create a Client SSL profile

You create a Client SSL profile when you want the BIG-IP system to authenticate and decrypt/encrypt client-side application traffic.
  1. On the Main tab, click
    Local Traffic
    Profiles
    SSL
    Client
    .
    The Client SSL profile list screen opens.
  2. Click
    Create
    .
    The New Client SSL Profile screen opens.
  3. Configure all profile settings as needed.
  4. Click
    Finished
    .
After creating the Client SSL profile and assigning the profile to a virtual server, the BIG-IP system can apply SSL security to the type of application traffic for which the virtual server is configured to listen.

Create a virtual server for MQTT

Before creating a virtual server, verify that you have created the pool to which you want this virtual server to send traffic.
When you create a virtual server, you specify a destination IP address and service port. All other settings on the virtual server have default values. You can change the default values of any settings to suit your needs.
  1. On the Main tab, click
    Local Traffic
    Virtual Servers
    .
    The Virtual Server List screen opens.
  2. Click
    Create
    .
    The New Virtual Server screen opens.
  3. In the
    Name
    field, type a unique name for the virtual server.
  4. From the
    Type
    list, for the virtual type, select
    Message Routing
    .
  5. In the
    Destination Address/Mask
    field:
    • If you want to specify a single IP address, confirm that the
      Host
      button is selected, and type the IP address in CIDR format.
    • If you want to specify multiple IP addresses, select the
      Address List
      button, and confirm that the address list that you previously created appears in the box.
    The supported format is address/prefix, where the prefix length is in bits. For example, an IPv4 address/prefix is
    10.0.0.1
    or
    10.0.0.0/24
    , and an IPv6 address/prefix is
    ffe1::0020/64
    or
    2001:ed8:77b5:2:10:10:100:42/64
    . When you use an IPv4 address without specifying a prefix, the BIG-IP system automatically uses a
    /32
    prefix.
    The IP address or addresses for this field must be on the same subnet as the external self-IP address.
  6. In the
    Service Port
    field, type one of these two port numbers, or select one of the two services from the list.
    Port Number
    Service Name
    1883
    MQTT
    . The Internet Assigned Numbers Authority (IANA) registered port for MQTT service.
    8883
    MQTT-TLS
    . The IANA registered port for secure MQTT service over a Transport Layer Security (TLS) network.
  7. In the
    Configuration
    list, retain the default,
    Basic
    .
  8. For the
    SSL Profile (Client)
    setting, from the
    Available
    list, select the name of the Client SSL profile you previously created and move the name to the
    Selected
    list.
  9. From the
    Application Protocol
    list, select
    MQTT
    .
  10. From the
    Session Profile
    list, select the name of a MQTT Session profile that you created previously.
  11. From the
    Router Profile
    list, select the name of a MQTT Router profile that you created previously.
  12. Configure any other settings that you need.
  13. In the Resources area, for the
    iRules
    setting, from the
    Available
    list, select the name of the iRule that you want to assign, and move the name into the
    Enabled
    list.
  14. Click
    Finished
    .
You now have a virtual server that listens for application traffic and acts according to the values configured within the virtual server.

View MQTT statistics

Ensure that an MQTT profile is assigned to at least one virtual server.
You can see how the BIG-IP system is handling MQTT messages by viewing statistics per MQTT profile.
  1. On the Main tab, click
    Statistics
    Module Statistics
    Local Traffic
    .
    The Local Traffic statistics screen opens.
  2. From the
    Statistics Type
    list, select
    Profiles Summary
    .
  3. In the Details column for the MQTT profile, click
    View
    to display detailed statistics about MQTT messages.