2531 - Configuring Grid DNS resolvers in NIOS

Scenario

While attempting to add an external NTP server, you team realized that while the Grid is providing DNS services to other devices on the network, the Grid members themselves cannot resolve names such as time.apple.com. Please update the Grid configuration to use the members ibns1.techblue.net (10.100.0.105) and ibns2.techblue.net (10.200.0.105) as the default DNS resolvers for the entire Grid.

The resolvers in NIOS do not have to be a part of the Grid, they can be set for any IP addresses that provide DNS resolution service.

Estimate Completion Time

15 to 20 minutes

Credentials

Requirements

• Administrative access to the Grid

Course References

• 2009: Configuring NIOS DNS Services

• 2023: Configuring NIOS DNS Zones

Lab Initiation

Access jump-desktop

Once the lab is deployed, you can access the virtual machines required to complete this lab activity. To initiate the lab, click on the jump-desktop tile and login to the Linux UI:

Username: training

Password: infoblox

Initiate lab

To initiate the lab, double-click the Launch Lab icon on the Desktop.

Choose the lab number from the list and click OK.

After clicking OK, you will see a pop-up message with a brief description of the lab task. If the description looks correct, click Yes to continue lab initiation.

Lab initiation will take a couple of minutes to finish.

Once complete, you will see another pop-up message with the login credentials and the URL for the Grid Manager’s User Interface. Note that the credentials may differ from those from prior labs.

Tasks

Task 1: Verifying resolver functionality

Verify both members ibns1 and ibns2 are configured to allow recursion from other Grid members.

Task 2: Configuring Grid DNS resolvers

Configure the NIOS Grid DNS resolver settings to use the IP addresses of ibns1.techblue.net (10.100.0.105) and ibns2.techblue.net (10.200.0.105) as the default DNS resolvers.

Task 3: Verifying DNS resolution from NIOS Grid

Verify the Grid can now resolve names, by attempting to add an external NTP server time.apple.com by name.

Solutions

Task 1 Solution: Verifying resolver functionality

There are 2 ways to execute dig from the Grid, from the Dashboard, or from the CLI.

Using dig From Dashboards

1. In the GM web interface, navigate to Dashboards → Status.

2. Scroll down to the Dig Request widget.

3. You want to make sure other members, such as ibgmc.techblue.net and ibrep.techblue.net can use ibns1 (10.100.0.105) and ibns2 (10.200.0.105) for DNS lookups. Use this widget several times to make sure you can successfully resolve external names such as time.apple.com. Screenshot below shows a dig originating from ibgmc.techblue.net to 10.200.0.105 (ibns2) to lookup the name time.apple.com.

   

Using dig From CLI

1. Switch to the console of the NIOS VM, and use the dig command from the CLI to perform the query to either ibns1 (10.100.0.105) or ibns2 (10.200.0.105).

2. You may use the commands dig @10.100.0.105 time.apple.com. and dig @10.200.0.105 time.apple.com. to verify DNS lookup functionality.

3. Screenshot below shows a successful query from one of the NIOS devices.

   

Task 2 Solution: Configuring Grid DNS resolvers

1. Navigate to Grid→Grid Manager→Members.

2. Click on Toolbar → Grid Properties.

3. Click on the DNS Resolver tab on the left.

4. Place a check mark next to Enable DNS Resolver.

5. In the Name Servers box, click add (+) twice to add two rows.

6. Click in each row and enter in the DNS server IP addresses: 10.100.0.105 and 10.200.0.105

   

7. Click Save & Close

Task 3 Solution: Verifying DNS resolution from NIOS Grid

1. Navigate to Grid → Grid Manager.

2. Click on the NTP tile near the top, to switch to the NTP services section.

3. Click on Toolbar → Grid NTP Properties. This brings up the Grid NTP properties dialog window.

4. In the section Synchronize the Grid with these External NTP Servers, click Add to add a new entry.

5. The Add NTP Server wizard appears.

6. In the section NTP Server (FQDN or IP Address), enter time.apple.com.

7. Click the button Resolve Name.

8. You should see a light blue banner across the top informing you the name can be resolved.