Use an Azure ARM template to create a high availability
(active-standby) pair of
BIG-IP Virtual Edition instances in Microsoft Azure. When one
BIG-IP VE goes standby, the other becomes active, the virtual server address is
reassigned from one external NIC to another.
Today, let’s walk through how to create a high availability
pair of BIG-IP VE instances in Microsoft Azure. When we’re done, we’ll have an
active-standby pair of BIG-IP VEs.
Click F5-azure-arm-templates.
Then go to Supported>ha-avset and
there are two options. You can deploy into an existing stack when you already have your subnets and existing IP
addresses defined but to see how it works, let’s deploy a new stack.
Click new stack
and scroll down to the Deploy
button. If you have a trial or production license from F5, you can use the BYOL
option but in this case, we’re going to choose the PAYG option.
Click Deploy and the
template opens in the Azure portal. Now we simply fill out the fields. We’ll
create a new Resource Group and set a password for the BIG-IP VEs.
When you get to the questions:
The DNS label is used as part of
the URL.
Instance
Name is just the
name of the VM in Azure.
Instance
Type determines
how much memory and CPU you’ll have.
Image Name determines how many BIG-IP
modules you can run (and you can choose the latest BIG-IP version).
Licensed
Bandwidth determines
the maximum throughput of the traffic going through BIG-IP.
Select the Number of External IP addresses (we’ll
start with one but can add more later). For instance, if you plan on running
more than one application behind the BIG-IP, then you’ll need the appropriate
external IP addresses.
Vnet Address
Prefix is for the
address ranges of you subnets (we’ll leave at default).
The next 3 fields (Tenant ID, Client ID, Service Principal Secret)
have to do with security. Rather than using your own credentials to modify
resources in Azure, you can create an Active Directory application and assign
permissions to it.
The last two fields also go
together. Managed Routes
let you route traffic from other external networks through the BIG-IPs. The Route Table Tag means that
anytime this tag is found in the route table, routes that have this destination
are updated so that the next hop is the IP address of the active BIG-IP VE.
This is useful if you want all outbound traffic to go through the BIG-IP or if
you want to send traffic from a bunch of different Vnets through the BIG-IP.
We’ll leave the rest as default
but the Restricted Src Address
is good way to put IP addresses on my network – the ones that are allowed to
connect to the BIG-IP.
We’ll agree to the terms and
click Purchase.
We’re redirected to the Dashboard with the Deployment in Progress indicator. This
takes about 15 minutes.
Once finished we’ll go check all the resources in the Resource Group.
Let’s find out where the virtual server address is located
since this is associated with one of the external NICs, which have ‘ext’ in the name. Click the one you
want.
Then click IP
Configuration under Settings.
When you look at the IP Configuration for these NICs,
whenever the NIC has two IP addresses that’s the NIC for the active BIG-IP. The
Primary IP address is the BIG-IP
Self IP and the Secondary IP is the virtual
server address.
If we look at the other external NIC we’ll see that it only
has one Self IP and that’s the Primary and it doesn’t have the Secondary
virtual server address. The virtual server address is assigned to the active
BIG-IP.
When we force the active BIG-IP to standby, the virtual
server address is reassigned from one NIC to the other.
To see this, we’ll log into the BIG-IPs and on the active
BIG-IP, we’ll click Force to Standby
and the other BIG-IP becomes Active.
When we go back to Azure, we can see that the virtual server
IP is no longer associated with the external NIC.
And if we wait a few minutes, we’ll see that the address is
now associated with the other NIC.
Basically, how BIG-IP HA works in
the Azure cloud is by reassigning the virtual server address from one BIG-IP to
another. Thanks to our TechPubs group and check out the demo video.
ps