Intro
Welcome to Part 6 of the AVI/ALB GSLB Lab In the previous post, we configured our DNS Delegation.
We are ready to test GSLB and hope it works as expected!
Testing
Load balancing across both sites.
First off lets load the website web.avi.lab.local, I’m running a chrome extension called Website IP which will show the IP of the site we are reaching in the bottom right corner of the screen.
First time around we can see it hit 10.10.0.50 which is the Web VS in DC A.
A refresh or two of the page and we can see we are now hitting 10.15.0.50 which is the Web VS in DC B so it’s working as expected 🙂
If we do an NSLOOKUP to web.avi.lab.local we can see that it is rotating between the two sites.
Next lets take a look at the DNS tables on the controllers to do this we SSH into the controllers at each site and then type ‘Shell’ then enter the credentials again. Type show virtualservice to see the Virtual Services on the controller.
admin@192-168-10-150:~$ shell
Login: admin
Password:
[admin:192-168-10-150]: > show virtualservice
+-----------+------------+-------------+----------+-----------+------------+----------------+--------+
| Name | IP Address | IP6 Address | Services | Cloud | Oper State | Type | Parent |
+-----------+------------+-------------+----------+-----------+------------+----------------+--------+
| web-vs | 10.10.0.50 | - | 80 | DCA-NSX-T | OPER_UP | VS_TYPE_NORMAL | - |
| dca-g-dns | 10.10.0.10 | - | 53,53 | DCA-NSX-T | OPER_UP | VS_TYPE_NORMAL | - |
+-----------+------------+-------------+----------+-----------+------------+----------------+--------+Now type show virtualservice ‘virtualServiceName’ dnstable. Below you can see the DNS A records for the web pools.
[admin:192-168-10-150]: > show virtualservice dca-g-dns dnstable
Sub Domains Serviced:
+-------------------+-----+------+------------------------------------------------------+-------------------+--------+
| FQDN | TTL | Type | Record Data | Service | Tenant |
+-------------------+-----+------+------------------------------------------------------+-------------------+--------+
| web.avi.lab.local | 1 | A | DCA-Webservers:10.10.0.50, DCB-Webservers:10.15.0.50 | web.avi.lab.local | admin |
+-------------------+-----+------+------------------------------------------------------+-------------------+--------+And on DC B
[admin:192-168-15-150]: > show virtualservice
+------------+------------+-------------+----------+-----------+------------+----------------+--------+
| Name | IP Address | IP6 Address | Services | Cloud | Oper State | Type | Parent |
+------------+------------+-------------+----------+-----------+------------+----------------+--------+
| DCB-Web-VS | 10.15.0.50 | - | 80 | DCB-NSX-T | OPER_UP | VS_TYPE_NORMAL | - |
| dcb-g-dns | 10.15.0.10 | - | 53,53 | DCB-NSX-T | OPER_UP | VS_TYPE_NORMAL | - |
+------------+------------+-------------+----------+-----------+------------+----------------+--------+
[admin:192-168-15-150]: > show virtualservice dcb-g-dns dnstable
Sub Domains Serviced:
+-------------------+-----+------+------------------------------------------------------+-------------------+--------+
| FQDN | TTL | Type | Record Data | Service | Tenant |
+-------------------+-----+------+------------------------------------------------------+-------------------+--------+
| web.avi.lab.local | 1 | A | DCA-Webservers:10.10.0.50, DCB-Webservers:10.15.0.50 | web.avi.lab.local | admin |
+-------------------+-----+------+------------------------------------------------------+-------------------+--------+Next if we open up the Web Virtual service on each site we can see the traffic that we generated.
DC A
DC B
DR Configuration
OK lets change the configuration for DR. First go back to the GSLB Services and edit it by clicking the Pencil
Edit the pool for DC A and set the Priority to 50. The higher the number, the higher is the priority of the pool. The DNS Service chooses the pool with the highest priority that is operationally up. So if the site stays up traffic will go to the primary site.
Now if we do several NSLOOKUPS they are now all going to DC A only
Lets simulate a failure, go to the DC A virtual services and select the Web VS and click DISABLE
Web-vs is now down.
This is reflected in the GSLB Services as well.
Again we do an NSLOOKUP and now traffic is only hitting DC B
And with that we are done, I hope you enjoyed the series and found it useful.