Lab 1.5 - Deploy Generic Host with Global Resiliency

In the previous lab exercises we deploy Global Resiliency using a native BIG-IP Next application.

In this exercise we will use a “Generic Host” that will allow you to target non-BIG-IP Next instances.

A Generic Host currently only uses an ICMP probe to determine the health of the host

Lab 1.5.1 - Edit Application

  1. Navigate to Applications

    Navigate to Applications by clicking the workspace switcher next to the F5 icon

    ../../_images/top-left.png

    Then click on Applications

    ../../_images/central-manager-menu.png

  2. Click on “gr_app” (previously created)

    In the upper right click on “Edit”

    Click on “Review & Deploy”

  3. Click on “Configure” next to “Generic Hosts”

Lab 1.5.2 - Configure Generic Host

  1. Fill in the properties

    Use the following values

    Property Value
    Name generic
    Health Monitor Gateway ICMP
    Generic Hosts’s IP Address 10.1.10.30

    Under “Virtual Servers” click on “+Add”

    Use the following values

    Note

    In this example we are using a FQDN to perform a lookup of the desired IP address to return

    Property Value
    Name generic_vs
    IP Address or FQDN fqdn-vip.example.com
    Port 443
    ../../_images/gr-add-generic-host.png

    Click on “Save”

  2. Click on “Deploy Changes”

  3. When prompted, press “Yes, Deploy”

Lab 1.5.3 - Open Web Shell

We will use the “dig” utility to verify our DNS records

  1. Within your UDF Deployment, go to the WEB SHELL access method that is under the Ubuntu Jump Host

  2. Type the following command

    # dig @10.1.10.53 gr.example.com +short

  3. repeat the command (you can use the up arrow to auto-complete) several times

    You should see 10.1.10.100 and 10.1.40.100 being returned

    ../../_images/gr-webshell.png

We are not seeing the new generic host entry because we have not configure the DNS Next instances to use the DNS server that has the appropriate name for “fqdn-vip.example.com”

Lab 1.5.4 - Override Next Instance DNS Resolver

By default BIG-IP DNS will use the DNS resolver that is configured via DHCP or during the setup of the Next instance.

In this lab exercise we will override the default DNS setting to point to a DNS resolver that has been configured to respond to the name ‘fqdn-vip.example.com’

  1. Navigate to Instances

    Navigate to Instances by clicking the workspace switcher next to the F5 icon

    ../../_images/top-left.png

    Then click on Infrastructure

    ../../_images/central-manager-menu2.png

  2. Click on “next-dns-01.example.com” to bring up the instance properties then click on “DNS” and “Edit” (top right)

    ../../_images/instance-edit-dns.png

  3. Under “DNS Servers” click on “+Create” and enter “10.1.1.6” and then click on “Next”

    ../../_images/instance-edit-dns-create.png

  4. Click on “Next” again

  5. Click on “Deploy”

Lab 1.5.5 - Verify FQDN VIP

We will use the “dig” utility to verify our DNS records

  1. Within your UDF Deployment, go to the WEB SHELL access method that is under the Ubuntu Jump Host

  2. Type the following command

    # dig @10.1.1.6 fqdn-vip.example.com +short

You should get back the IP address for the name.

  1. Type the following command

    # dig @10.1.10.53 gr.example.com +short

  2. repeat the command (you can use the up arrow to auto-complete) several times

    You should see 10.1.10.100, 10.1.40.100, and 10.1.10.30 being returned

    ../../_images/gr-webshell2.png